3D Vinci (http://www.3dvinci.net/ccp0-display/freestuff.html) has downloadable pdf lesson plans to teach math concepts using Google’s Sketchup. The site also has an impressive collection of printable puzzles and mosaics for students in kindergarten through twelfth grade to solve. This site helps bring 3-D concepts to life in a way that textbooks can’t. 3D Vinci also has a YouTube channel where students can watch several ModelMetricks projects.
Also from: http://ilearntechnology.com/?p=3647