Board Game - Let Play a Game: Play by forum?

I've been playing a game of Hive through email with a co-worker for a few months now using GIMP. Basically through the magic of layers and transparency I have created a full set of the hive game.

Anyhow I was wondering if there are any other simple games we could play using things like drop box or google docs.

I dont want to get anything like dungeons and dragons just something simple.

Just so everyone gets the idea just grab the file below:
https://docs.google.com/leaf?id=0B4j...

Open it up using GIMP:
http://www.gimp.org/

Make your move and upload it to your favorite site.

Note:

If this type of forum use is not appreciated I would gladly switch to PBEM or PM.