I don't know if anyone's noticed this rash of communities of Livejournal, but I thought it was a great concept and I encourage everyone to sign up or even just take a look at the prompts if you need some inspiration for your artwork. Fanart 100
100 prompts for 100 drawings of the fandom/character/pairing or your choiceFanart 50
A slightly less strenuous version of the aboveEyecandy 69
An um... very raunchy version of the above
I was very tempted to sign up for Fanart 100, but wimped out at the last moment and signed up for Fanart 50 instead. The prompts are more interesting over there, anyway. :P My fandom is Weiss Kreuz: General. So far, it's been very challenging and fun.
You could probably even modify these for original characters, if you like.
(There's also an eqivalent for fanfiction, but that should probably go in a different section on the forums. ;) )