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!
You choose which sets of multiples you would like to test your students on and number choices are created for you. Then drag them up to the correct part of the Venn Diagram. A great iwb resource!