– You could put a tilt sensor on a toilet flusher so it tweeted every time someone went into the bathroom.

-you could have a camera placed somewhere (like a doorway) and every time someone walks through the doorway, their picture is taken and then posted on twitter.

-you could put a gps in your shoe and tweet your location every so often.

-some sort of sensor that detects movement (tilt maybe?) in combination with a lillypad arduino so that every time you got undressed it tweeted.

-Place a radiation sensor in the labs around campus, doherty studios too, and have it tweet every so often