[ame=http://www.youtube.com/watch?v=IA9J9FFqK18]YouTube - iOS 5 Syncing Lets You Use Your iPhone, iPod Touch, Or iPad - iOS Vlog 437‏[/ame]
Ever since 1.0, iOS 1(if you will), we haven't been able to use our iDevices while they were syncing. This was a problem because syncing takes a lot of time especially if you have to transfer a whole bunch of data. Apple has made syncing a bit faster since the iOS 1 days but you still might miss that vital call, SMS, or email while wired in. With the iOS 5 update, Apple has brought us the ability to use our devices while they sync. All it does is add a small indicator in the status bar so we know that it still needs to be plugged in. There are a few tweaks in Cydia that currently allow you to do this, but then again, there a lot of tweaks in Cydia that do many of these new features.