The Rational Druid

Open Circuits provides a site full of ideas and circuits put into the open source community. Using their description:

Open Circuits is a wiki for sharing open source electronics knowledge, schematics, board layouts, ports and parts libraries. This include open hardware Music Players, atomic microscopes, PC, PDA and mobile phones, and batteries.

Visit, and add what you can.

I just saw this site this morning. I found the link in Make magazine (awesome magazine, by the way). There is far too much info here for me to go into. All I can say is that you need to go check this out if you have any interest in physics or science.