i just found this, so i wanted you to know 2: http://musart.dist.unige.it/sito_inglese/research/r_current/eyesweb.html
much "simpler/easier" than pd, but that motiontracking worx even on my old p2 350mhz @ 160x120x25fps... so i'm using my webcam as a controller for PD... momentarly a "d-beam" clone with X & Y & Z coords...
note: on win98 it worx great (even when theres an error while installing) on win2k it worx but i'm unable to save or open files... (due the missing developer versions of DLLs ?!?!) and the reg.hack tips on their news-server doesen't help...
if some1 gets it to save&open on win2k, PLEASE let me know
cheers -andre