The World Education Games take place 6-8th March 2012. Here's a link to their site.
http://www.worldeducationgames.com/ so you can see what it's all about. There's a video here where members of the public are unable to answer some very simple questions.
If you have any bright sparks in your class then get them to have a go. Your Head might be pleased with you if somebody won a medal. When the kids ask you if there's any decent prizes, just blather something about the Olympics.
By the way if you have any seriously bright kids then you might want to look at the British Maths Olympiad http://www.bmoc.maths.org/
which is a qualifier for the International Maths Olympiad.
http://www.imo-official.org/ (North Korea has been disqualified twice for cheating)