USB 3D Arm Input Device
Olin has a class called Principles of Engineering where students work in teams the entire semester creating their own "mechatronic" project. When I took the class the focus was on making a USB device. Mark Cavolowsky, Zac Borden and I created a 3D input device. They did the main mechanical design, while I did the PIC assembly programming and the host computer software for interpreting data from the arm.
We intended it to be a drawing device, but the potentiometer resolution wasn't that good. Occasionally I still use it to interact with 3D objects.
The project website can be found here.