I have a comic book based site, but this could work for sports site too.
I'd like to see a hack (integrated with vBadvanced CMPS) where you could enter characters or teams in a versus style, have the outcome decided by a poll (useful for members voting on a victor, i.e. Superman vs Green Lantern, etc) or manual entry (in the case of sporting events) and have the victor move on to the round of eliminations, and continue until you have a winner for the entire competition. You could then announce the winner.
What I'm thinking is like the NCAA bracket standings similiar to the attachment below except that you would obviously input the teams/characters instead of writing them in with a pen. When a winner is decided at each match up they move on to the next elimination round.
I hope I made what I'm asking for clear, I feel like I haven't explained it as well as I wanted to.