A colleague of mine Tristan Mether who has just completed the DEECD Videogames in the classroom trial has put together a great website full of maths lessons that can be undertaken on a nintendo Wii.  They are thoroughly detailed and full of worthwhile activities.

The WiiMaths Project is aiming to investigate how the Nintendo Wii can used in conjunction with Mathematics Teachers and Curriculum Program. (M.T.C.P.) to create updated handson activities and reengage the students of 21 century in mathematics?

This project uses the MTCP (Mathematics Teachers and Curriculum Program) written by Charles Lovitt & Doug Clarke and updates the practical component (previously video tapes and other stimulus materials) using the Nintendo Wii and its games to now give students a hands on experience (of large events like ten pin bowling) within the classroom.

In this way they can link the maths topics and solve problems as the play along in the class. It also is links into educational research being done by Derek Robertson at the Consolarium in Scotland (Centre for Games and
Learning http://www.ltscotland.org.uk/ictineducation/gamesbasedlearning/ ) around Games-based learning.