Apple unveiled iPhone OS 3.1 at today's "It's Only Rock and Roll" event in San Francisco. In addition to some new features, the software update contains all of the functions introduced previously in 3.0. Version 3.1 is available now, so if you've been looking forward to its release, be sure to upgrade and share your thoughts in the comments.

Among the more noteworthy additions brought with 3.1 is "Genius" app recommendations, which feeds you apps based on software that you've already downloaded. Other features include the ability to download ringtones wirelessly, organize apps in iTunes, redeem iTunes Gift Cards and view account credits in the App Store, save video from Mail and MMS into the Camera Roll, remotely lock an iPhone with a passcode via MobileMe, paste phone numbers into the keypad, and several more.

If you are still waiting for MMS support, AT&T is expected to launch the feature a little over two weeks from now on September 25.