In Steve Jobs' keynote announcement of the iPhone SDK 4 earlier this year, one of the slides showed that a "Half curl page transition" was part of the new SDK.
I've looked through the iOS API docs and I can't seem to find this transition. Does anyone know where it is?
It's not a transition, but a modalTransitionStyle. You can check the docs here: https://developer.apple.com/documentation/uikit/uiviewcontroller/1621388-modaltransitionstyle
If you create a new UIViewController, set its modalTransitionStyle to UIModalTransitionStylePartialCurl, and then presentModalViewController:animated: it, you'll get the desired "half curl page" effect.