Apple announced iOS 5.1 alongside the new iPad at a media event less than 24 hours ago. The incremental update was made available shortly afterwards and the iPhone Dev-Team has already released a jailbreak for the update, although there are a few caveats that potential users should be aware of before installing.
The latest jailbreak is of the tethered variety. This means that if you have to reboot your handset or you accidentally drain the battery to the point where the iPhone turns off, you will have to use a PC or Mac along with redsn0w's "Just Boot" to regain jailbroken app functionality (Safari won't work, either). Furthermore, iBooks isn't supported in this release.
The jailbreak only works on non-A5 devices, so users hoping to do the deed on their iPhone 4S, iPad 2 or the new iPad coming out next week are currently out of luck. Either way, we suggest heading over to Think iOS to get the full details before proceeding.
At 199MB, iOS 5.1 offers a number of improvements and bug fixes including but not limited to Japanese language support for Siri, improved audio that sounds louder and clearer on the iPad when watching TV shows and movies, a redesigned camera app for iPad, an updated AT&T network indicator and a camera shortcut that's now always visible on the lock screen for iPhone 4s, iPhone 4, iPhone 3GS and iPod touch (4th generation).