well, this is something i saw on the cgtalk forums, and quite enjoyed watching.
sprite battles.
purpose: entertainment.
administrator: not sure.
there are 2 versions that i saw:
1. background version:
- one guy starts off by doing something on the background (eg320x200), eg he draws a castle.
- then the second guy draws something to counter the first guy's sprite, eg, he draws an invading army with catapults thats attacking the castle.
- then the 1st guy again counters with, eg a force field.
- this continues until the background is filled and no more space left.
- you are allowed to alter the other guy's drawing a bit to make your own work.
- in the end it will come down to voting who added the best ideas.
- 2 can take part, or many more. everyone can take part in this one.
- period: till the background is filled.
2. character/object version
- two members compete against each other.
- both of them design their own unique sprite
- then, these two sprites are in war against each other.
- the first guy draws the sprite of how his character attacks the other character
- then the other member must counter the attack with his character,
- anything goes. creativity is key.
- again, voting will decide.
-period:depends, if you run out of ideas, the comp is over.
these things are really fun to watch and follow how the picture/battle evolve.
although, im not sure if this will work here.
anyway, its just a thought.

would probably also not work as a weekly thing, more as once every few months or something..