Busy is an understatement lol. However RIM has a Tick-Tack-Toe demo that they provide to developers. I can upload that if you guys would like it. I've never played it myself but it's worth a shot.
unforunately rim's app doesnt really have great ai. its impossible on hard as dmg said, and very easy on easy. and it always reacts the same way, there is no randomness to the ai.
just checked it out on the emulator (left usb at work) and works good. multiple difficulty levels. Very basic GUI but works as explained. I say go for it for whoever wants a tic tac toe game