Make Zine is an awesome resource for DIY projects across the board, but they also have a variety of arts and arts-related technology projects that could easily work in the classroom.
Just a sample of projects on their site:
Moving Papercraft Toys, Egg Carton Rainbow Hats, Chalkboard Cloud Mobiles, Electronic Cards, Dyed Play Silks, and tons more!
http://blog.makezine.com/projects/
It’s also worth mentioning that there are a number of interesting articles on “lost technologies” on their blog, including how to make early optical toys/inventions like phenakistoscopes and magic lanterns.
Magic Lanterns: http://blog.makezine.com/2010/03/09/lost-knowledge-magic-lanterns/
Phenakistoscopes: http://blog.makezine.com/2008/08/10/build-phenakistoscope/