I did this a few years ago for the World Cup, so going to do it again for the upcoming Euro's. The prize is to be decided, probably will just be a £10 amazon gift voucher depending on my finances at the time.
Only rule for joining is you have to have 100 posts. Exceptions in certain circumstances will be made though. First 24 people to post will be given a spot, and when all 24 spots have been filled the draw will be made using this