Earlier today Apple quietly released iOS 6.1.1, an update only for the iPhone 4S that fixes spotty 3G issues.

Christian of iDownloadBlog stated:

The update with the build number 10B145 fixes an issue that could impact cellular performance and reliability for iPhone 4S, per release notes accompanying the paltry 23MB download.
The biggest worry was, "Will the update break evasi0n?" And, luckily enough the update didn't break the ingenious jailbreak, but the evad3rs did have to release a new version because of some small changes. In a tweet sent out earlier, the evad3rs notified everyone that evasi0n 1.3 with support for iOS 6.1.1 on iPhone 4S has been released.

If you aren't having any problems, don't update. If you already have, grab the update from http://evasi0n.com/ and rejailbreak.

If you are already jailbroken on iOS 6.1 and want to update to iOS 6.1.1, do not try to update Over The Air. It will fail and you will have to restore. First, make a backup of your device in iTunes. Then, restore and update in iTunes.

Thanks to iDownloadBlog: