since skritter isn't going to be coming to wp7 any time soon, and while waiting for the iOS app to come out so I can learn on the run on my ipad, I built a little chinese word game for anyone else out there who's got a windows phone:
http://henry-chong.com/wuxie/
Take a look, let me know what you think - it's no skritter, but every little bit helps :)