From the Open University's Open Learn site.
Identify rotation and translation symmetries in wallpaper patterns. Think this will work well in class, but uses click & drag, so will probably use a wireless mouse rather than the IWB.
An interactive maze designer - I think that this would be great for an interactive whiteboard. It's part of a site full of interesting pictures, photos and information about mazes. I approached the author, Jo Edkins, about using some of the materials and got a really nice reply. More info about permission for use in schools is here: http://gwydir.demon.co.uk/jo/about.htm
Jo Edkins has also created lots of other webpages - http://gwydir.demon.co.uk/jo/index.htm - I need to start exploring!