We’d be remiss if we didn’t mention [Johnny Lee]‘s interactive whiteboard right off the bat. His software uses a LED light pen and a wiimote to detect the users actions. If you’re looking for the code, hit the second project on this page. Oh, and don’t forget his automatic projector calibration project.

LumenLab projectors are just the thing for the true DIYer. Take a standard desktop or laptop LCD, strip the casing, add some optics and a decent light source (Metal Halide works great) and you’ve got your own projector. They can produce HD quality or be built as cheaply as possible. We wrote up our own build a while back for engadget.

If you’re considering building your own, you should look into some of the nicer custom projector controller projects, like the P-Brain.

We’ve seen a few DIY screens. The blackout cloth version, the tyvek/PVC version and the mix your own paint version and the DIY electric version.