A research team from the GroupLab at the University of Calgary is working on a set of new single-handed gestures for the iPhone called the the Fat Thumb interaction technique. This technique lets you hold your iPhone with one hand and use your thumb to interact with the UI.
The team conducted a trial that challenged users to pan and zoom to a location on a map and the Fat Thumb interaction technique performed as well as other commonly-used multi-fingered techniques. You can read more about the gestures in the group's 10-page PDF research paper and watch
