If you like learning about low power or messy signal stuff, there's some research at UW several years back about using e.g. a combination of em interference fro

If you like learning about low power or messy signal stuff, there's some research at UW several years back about using e.g. a combination of em interference from human bodies and normal house electrical wiring/lightbulbs as motion detectors. That sort of stuff is really cool, and I'm very impressed by people like Jeri who can actually make it work.