Apple this week, making the service available to public users five months after its introduction and a few weeks later than expected. The , meant to sync an entire music library over iCloud for easy access on other devices, has already thrown some users for a loop—Apple had to stop taking new subscribers yesterday thanks to too-high launch volume, and others were frustrated by Apple's limit of 25,000 non-iTunes-bought tracks.

The service seems to be back up and accepting new signups again, however, and plenty of users are finally getting the ball rolling on matching their iTunes libraries in the cloud. But the service isn't necessarily as straightforward as it seems, and there are plenty of questions floating around about how, exactly, Apple determines which songs to "match," which to upload, and which to leave behind. We put together the answers to some of the most common questions and problems we've seen so far in hopes of clearing up confusion about how iTunes Match does and doesn't work.

Steve wept. And unlike Jesus, who famously wept once, Jobs cried all the time. He cried at the beginning of Apple after Woz's father pushed his son to take more ownership of the company because he thought Jobs wasn't doing much work. Jobs went over to Woz's home and bawled his eyes out. Woz kept him on.

Jobs cried when his employee badge said #2 instead of #1 (which went to Woz), then demanded to get badge #0. He cried when Apple pushed him out of the company. He cried at Pixar during a battle with Disney. He cried when Time made the Mac its "machine of the year" instead of naming Jobs as "man of the year." He cried when he saw the famous Apple "1984" ad for the first time. He cried about Windows "copying" the Mac.

He cried over design questions, like when the iMac team put a tray-based CD drive in the machine rather than a slot-loading drive. He cried over deep issues of personal privacy, such as the moment his cancer first became public and shareholders were braying for information. He cried because he wanted the original Apple II to have a two-year warranty, rather than 90 days.

Apple has to the public, which enables support for its iTunes Match service. The service allows syncing your music library to iCloud for easy remote access from other computers or iOS devices. But don't get too excited just yet, as iTunes Match's hard 25,000 track limit means those with extensive collections simply cannot take advantage of the service.

is a subscription-based iTunes library syncing service that works with iCloud. Unlike Amazon Cloud Player or Google Music services, iTunes Match can identify tracks in your library that are already part of the iTunes Store's extensive library of music. Those tracks are immediately added to a user's iTunes Match account by connecting to the 256kbps, DRM-free version on Apple's servers. This is true even if you ripped the album yourself at lower bitrates using older versions of iTunes or other software.

The remaining tracks, up to 25,000 total, are then uploaded to iCloud. Any songs purchased directly from iTunes don't count toward this limit, but if you have more than 25,000 tracks not purchased from iTunes in your library, the service simply refuses to let you sign up. Apple has yet to make any allowance for users with massive libraries to choose a subset of their music to upload—an unfortunate limitation in our view, since such avid listeners are among the most likely to consider paying the yearly $24.99 fee.

On the upside, iTunes Match also syncs all of your playlists across devices. Once your library is uploaded and synced with iCloud, you can turn on iTunes Match on an iOS device and access individual tracks, whole albums, all songs by a particular artist, or any of your playlists. Clicking the small iCloud icon downloads the files and adds them to the library on a particular device, while selecting an individual track appears to merely long enough for playback.

Apple missed the for iTunes Match by a couple weeks, re-releasing iTunes 10.5.1 betas for testing by registered developers over the last month and a half. At the time of publication, the final version of iTunes 10.5.1 was not available from Software Update, but it is available as a from itunes.com.

UPDATE: Fortune reports that iTunes Match is , with Apple's servers unable to activate new users. Apple is recommending trying again in an hour or two, though we, like Fortune, recommend maybe waiting longer if you're not in any hurry.

Have you ever had an iPod nano catch fire on you? Even if you haven't, if you still have a first-generation iPod nano, the risk is there. Six years after the introduction of the original nano, Apple has in order to address potential battery overheating issues.

Apple began notifying users late Friday about the replacement program. According to the company: "This issue has been traced to a single battery supplier that produced batteries with a manufacturing defect. While the possibility of an incident is rare, the likelihood increases as the battery ages." The company recommends that users stop using their first-gen iPod nanos sold between September 2005 and December 2006 and apply for a free replacement through its website.

Those with long memories may recall that there was a series of laptop battery recalls that took place throughout the fall of 2006, with big names like , , , and replacing the lithium-ion batteries in many of their portable products. In August of 2006, Apple issued a statement saying that "microscopic metal particles" in its battery cells manufactured by Sony could lead to a short circuit, leading to potential overheating issues and even fires.

It certainly sounds as if the first-generation iPod nano batteries are suffering the same fate, as they were manufactured and sold during the same time period as the laptop battery fiasco. Complaints about the original nano began in Japan and South Korea not long after (starting in about 2008), with Apple eventually agreeing to in those countries. Now, it looks as if Apple's replacement program is just being extended to cover the rest of the world, so if you still have one of these in rotation (as I do, strangely enough), you may want to get it replaced so you don't wake up one night to iPod nano flambé.

This week in Apple news, we talked to security researcher Charlie Miller about a flaw within iOS that ultimately got him suspended from Apple's developer program. Apple then issued an update to iOS 5 that fixed that bug in addition to a handful of others. We also covered a MagSafe connector settlement, Instagram clients for the desktop, GarageBand for iPhone, Apple's new self-checkout system at its retail stores, and more. Read on for the roundup!

: Apple has made good on its promise to deliver an iOS 5 software update to address battery life bugs. But does it work?

: Security researcher Charlie Miller has found a crack in iOS's sandboxing foundation that could let any app run unsigned, unvetted code. His proof-of-concept app earned him a one-year suspension from Apple's developer program, too.

Move over, iOS: CoreLabs Research has posted a of a potential security vulnerability in Mac OS X's sandboxing mechanisms. According to CoreLabs, it's possible for sandboxed apps to trigger external processes that aren't sandboxed and possibly gain privileges not granted by a particular sandboxing profile. The revelation comes shortly after distributed via its Mac App Store to use sandboxing, ostensibly to increase security for Mac OS X users.

Apps that conform to Apple's use a set of "entitlement" profiles defined by Apple; those profiles determine which system resources it can use and which are off limits. CoreLabs discovered that some of the limits in the default profiles can actually be circumvented by triggering certain Apple Events. In particular, Apple Events can cause launchd to launch a separate process without sandbox restrictions.

Those who held off on an iPhone 4S purchase until the unlocked version became available can now whip out their credit cards—but it's gonna hurt. Apple began selling unlocked versions of the iPhone 4S via its Friday alongside a handful of international iPhone 4S launches—the phones don't require the typical two-year contract and only work on GSM networks.

The unlocked, contract-free iPhone 4S will cost $649, $749, and $849 respectively for the 16GB, 32GB, and 64GB versions. That's $450 more per device than the carrier-locked versions, but there are plenty of reasons to not want to be tied to a single carrier. As by Apple, those who travel abroad regularly and want to use local GSM networks instead of roaming on their US network will benefit the most—just obtain a micro-SIM card from a supported GSM carrier and pop it into the iPhone's micro-SIM slot, and you're set.

(As noted by , Apple's retail stores began selling no-contract iPhones immediately after the 4S launch, which also appeared to be unlocked, but the official launch of the unlocked devices was not until today.)

On the other side of the coin, what looks like a leaked memo posted to appears to show that Sprint plans to begin SIM-locking its iPhones starting Friday. This is not a particularly shocking development—a in October that the company was selling unlocked iPhone 4Ss for a limited time, but that they would begin locking the devices "shortly after launch." That day is apparently today, though Sprint did say that the devices could be unlocked again. "We will then allow existing customers in good standing to unlock the SIM for international use if needed in the future," the company told Ars.

As promised, Apple has released an update to iOS 5 that purports to fix bugs within the operating system that affected the battery life of its devices. The 5.0.1 update is relatively minor otherwise—in addition to the battery life bugs, Apple says it contains improved voice recognition for Aussies using Siri for dictation, adds multitasking gestures for the original iPad, and resolves bugs related to Documents in the Cloud.

Apple last week after numerous reports began popping up online from dissatisfied iPhone 4S owners. While the problem didn't seem to affect everyone who bought an iPhone 4S, appeared on Apple's discussion forums from users who were getting much less life out of their iPhones than expected. Since then, there have been plenty of suggestions posted online for how to improve the situation, such as turning off location-based Reminders (which requires your phone to monitor your location more frequently), turning off Siri (or at least the "raise to speak" feature), turning off Bluetooth, and turning off push notifications.

When Apple acknowledged the problem, the company said that a "small number of customers have reported lower than expected battery life on iOS 5 devices. We have found a few bugs that are affecting battery life and we will release a software update to address those in a few weeks." Indeed, developers who had early access to iOS 5.0.1 reported on Twitter that their iPhone 4Ss did seem to squeeze a little more life out of their batteries after the update, and now that it's available to the public, we're about to find out on a larger scale whether that's true.

Nuance released on Thursday a new speech-to-text app for Mac users called . The pared-down app features the same speech recognition engine as its full-featured, $199 cousin Dragon Dictate, but at a much lower price.

We have already  Nuance's Dragon Dictate, which offers features like direct, in-app input, voice-based editing controls, voice commands to control you Mac, and . Dragon Express is more akin to Dragon Dictation on iOS—activate the app (you can configure a hotkey), say something out loud, and your speech is converted to text. The text can then be sent to the clipboard and pasted into any other app. It can also be sent to any active text box in any currently running native Cocoa app.

Nuance said that Dragon Express can work with either your Mac's built-in mic or an optional USB headset. We haven't been able to test the app's accuracy without a headset just yet, but our experience with the iOS app suggests it should be good enough to at least give you a workable rough draft. If your typing speed isn't that great, or hampered by a repetitive-stress injury, Dragon Express could be a big help.

Dragon Express has a few more tricks up its sleeve, too. Using a limited selection of voice commands (or merely clicking the requisite icon on the app's toolbar), you can send the translated speech to Facebook, Twitter, in an e-mail, perform a Spotlight search on your Mac, or search online using Google.

Dragon Express only runs on Mac OS X Lion and is available now for an "introductory" price of $49.99.

It's not often that Apple buries hidden features within public releases of iOS, but two previously unknown features within iOS 5 caught the attention of developers this week. The first, discovered on Monday by developer , is a panorama mode within the iOS 5 Camera app. The second, discovered Thursday morning by iOS hacker , reveals an "Android-like" autocorrect bar above the on-screen keyboard.

Both features appear to have been tested by Apple for iOS 5 but were not included in the final release for whatever reason. Regardless, users can still enable them both on their iOS devices by using a tool called to manipulate your iPhone or iPod touch's backup file. Detailed instructions for exactly what to add to which files can be found at for the panorama mode, and for the keyboard autocorrect bar.

Neither of these require jailbreaks, but they do require some poking around in files that Apple doesn't like people to mess with, so use the requisite caution when doing so. If you are a jailbreaker, however, developer Grant Paul has an app called Firebreak to Cydia in order to enable the panorama mode.

if you ask us, panorama mode is much more interesting than the keyboard hack—it appears as though the latter is simply a different way of displaying the same autocorrect suggestions that iOS already provides. Then again, there are available to users already, so if you're looking for the easiest way to start taking those kind of photos, the App Store may be a more attractive place to start.