I was curious to find out if there is something as powerful as http://impactjs.com/ , but open source, to make it easier to develop a game by phone stutter.
you can try the hits: http://code.google.com/p/playn/
I doubt that it currently works well (or in general) with Phonegap, but I loved Crafty for developing HTML5 games on the desktop and I plan to start making improvements for mobile devices in this project.