Absolutely gorgeous. Will be interested to see how our iOS version goes. I'm not sure if it will be of any help, but I have written an interaction "helper" library that is designed to make handling mouse and touch events consistent. If it is something that is useful, then let me know if you have any questions or suggestions.
Damon, the iOS version is being written natively for that platform in Objective-C. I've got many ideas to explore on the iPad and iPhone/iPod -- what's on the web is just a taste.
But thanks for the link! I'll keep it in mind if a use for it crops up.
http://sidelab.github.com/interact/