I just presented Eye-Contact Sensing Glasses and eyeBlog at CHI 2004 in Vienna, Austria. ECSGlasses and eyeBlog are a video recording and publishing system that responds to human social interaction. It uses a wearable, wireless Eye-Contact Sensor (1.3MB .jpg) to gauge when the user receives eye-contact from an onlooker. eyeBlog uses this information to record and publish face-2-face conversations without dividing the user's attention between the event being recorded, and the device being used to record it. Moreover, becasue eyeBlog uses eye-contact to start and stop recording, users do not need to sift through hours of footage to find interesting segments.
If you are the academic type you can read the paper (2.2MB .pdf), otherwise the video in .mpg (1:49min, 320x240, 7.5MB), or mp4 (1:49min, 320x240, 4.9MB) should explain everything.
~ Special thanks to David Fono and the rest of the hml crew.