Johnny Lee demos his wiimote whiteboard and wiimote headtracking/3D applications at TED 2008.
Uwe Schmidt has made an excellent Mac OS X version of wiimote whiteboard in Java (he also has a cross-platform version available). It is available from his website - http://www.uweschmidt.org/wiimote-whiteboard - and includes TUIO support for multitouch.
Lots more information about Johnny Lee’s projects and other peoples additions to them is available on the Wiimote Project site.