I just found a neat little website. It is a monthly photography contest. You are only allowed one upload for each month. Each month has its own theme (and I am all about themes!) and the picture uploaded has to be geared to that theme.
This sounds like fun :)
Check it out
http://www.proudphotography.com/forum/showthread.php?p=15591#post15591 (this is the list of themes for each month)