Hopefully it's ok to post other painting competitions here, not just the ones hosted on this site. If not, my abject apologies. Anyway.
There's a spontaneous and fairly informal modelmaking/painting competition going on at The Speakeasy, the forums for Rattrap Productions, publishers of fine narrative adventure minis games such as .45 Adventure, Gloire, Fantastic Worlds, Broadsword Adventure, etc.
Basically, make a raygun-pulp jetbike out of parts, post a painted pic, parts list, and cool writeup about the pilot by November 30th.
The contest thread is here:
http://rattrapproductions.com/speakeasy/viewtopic.php?t=1273