As long as I'm here... guidelines.
1. Image Size: 320 x 240. I find it's fairly easy to deal with all the entries if they're all of similar size.
2. You all should decide on a topic (I know, I'm restating the previously stated) AND possibly some artsy guidelines to follow, such as:
I. Must be Black and White
II. Must use the 'Oilify' GIMP effect
III. Must involve rain
... you get the idea.
Also, if you'd like, kidko has a topic generator he coded just for these kind of things.