And, I'm done!
Check it out:
http://www.bitmadness.com/It's a free, ad-free way to run a march madness pool, with or without bitcoins!
No limits on number of users, pools, nada!
It uses the new mtgox payment API also for all the bitcoin stuff!
Give it a try and give me some feedback! As soon as the teams are announced later today, I'll update the site with the full bracket!