WelcomeSwitch -- Lets members indicate when they're willing to accept guests.
CupcakeCar -- A goofy testbed for electrical and mechanical ideas, an eye-catching way to zip around town, and an engineering disaster, all rolled into one!
Player Piano Rebuild w/ Roll Printer -- Rebuilding an old player piano to working condition. Then hacking an old dot matrix printer to cut out from a continuous roll of paper to play on the piano, as well as various piano add-ons for further automation.
Feedback Slider -- A musical instrument based on feedback.