PoolExpert.com is a great website that compile stats and would do all the work for us. I tried it 2 years ago with 15 other poolers and we all had a blast. You have access to a lot of statistics like "Best week, best month, best day" and so on. If you want to see an overview, you can click
here
The thing is, it would cost 2$ per person (to a maximum of $30).
If everyone absolutely want something free, I think onlinepools.com doesn't cost anything... But I didn't try it so i don't know if it's good.