Looking to exchange ideas for arduino. Not looking to repeat those ideas from a thousand times before. You know the ones: light dimmers, robots that go in circles around the living room, LED light show, indoor/outdoor thermometer that opens and closes curtains, automatic turn off of your multimedia center when the music stops, etc. This is meant to be a brainstorming session where no idea is considered too ridiculous. Not allowed to say "you can't do that because..." Here's a few to prime the pump: 1) How about a seriously great power line monitor that reports voltage, current, harmonics, source impedance and notifies you by SMS text when something goes out of tolerance. 2) Seismic disturbance monitor that uses a very sensitive transducer fastened to your house concrete foundation. 3) Non-contact lie detector that senses stress levels in a speaker's voice. Must be able to distinguish between stress and distress.