I've been wondering if it is possible to replicate the behavior of Apple's iOS5 keyboard in the messages app, without using any private API calls. When you scroll down past the keyboard in the messages app, the keyboard will collapse leaving more room to see messages - try it to see.
I couldn't find anything that points towards making this without having to start jumping through some serious hoops to get an instance of the Keyboard's View. And I'm pretty sure Apple wouldn't be happy with that.
In addition to the answer given below you can see a fully baked xcode project of my implementation here: https://github.com/orta/iMessage-Style-Receding-Keyboard
In iOS 7 there is a keyboardDismissMode property on UIScrollView. So just set it to "UIScrollViewKeyboardDismissModeInteractive" and you'll get this behavior. Works in UIScrollView subclasses such as UITableView.
self.tableView.keyboardDismissMode = UIScrollViewKeyboardDismissModeInteractive;
Swift 3:
tableView.keyboardDismissMode = .interactive
Or change it in storyboard (if using it) in attributes inspector for your UIScrollView subclass.