"Guzman", a member of Classroom 2.0, is a math teacher in Florence, Italy who teaches math to middle school students. In addition to math, he has an IT background. He used Google Sketchup to introduce and work with solids. He thinks that Sketchup would be a good tool to use to teach volumes, sections, and more.
Guzman's student's worked on this project one hour a week for five weeks, and created all of the models using Sketchup. The animation was created with Sketchup by Guzman.
You can find the models Guzman's students made at Google 3D Warehouse
Tom Barret, at Classroom 2.0 has started a Multi-Touch Interactive Desk Development group. Tom is involved in the SynergyNet: Multi-touch in Education research, which is part of Durham (UK) University's Technology-Enhanced Learning Research Group.
You can find related pictures on Flickr: Multi-Touch Interaction: Applications and Gesture Ideas