We’ve covered a few ideas for technology on the cheap before, but this one may take the cake. The article has been posted on a couple of other boards including the classroom 2.0 Ning.

Johnny Chung Lee of Carnegie Mellon University has designed a project for creating an interactive whiteboard out of a Nintendo Wii Remote, an IR LED light, and of course your projector. The price? $50(projector not included). The site has a video demonstration, details on how to make the pen, and includes the software for running it.

The concept behind it is that the Wii remote uses an IR camera that tracks the movement of anything giving off IR light. So by constructing an IR pen with spare parts from a keychain, and using software that he wrote(free) you can use the pen just like you would use the pen that comes with expensive whiteboards for writing, mouse emulation etc…

Here’s the link.