I think that it could be possible to implement gestures in the home screens of the iPhone (I lack the handy shortcuts of Nokia phones, up, down, left, right for creating a new message, see last calls… etc…).

You could use two finger swipes (up, down, left, right) to do this kind of things (maybe a panel to configure these actions could also be useful…). Perhaps also a three finger swipe could make it.

[updated]

You could link the swipes to several common action or to launch 3rd party apps or custom urls (to use special url schemas)