Wow.... That is something i've never seen before. It looks like a lot of fun! No clue as to how it is done though.. Have you tried to contact the video's uploader?
It's a shape follower called sticky light (another project is scorelight) ..... i'm trying to find this software from at least 6 months, searching on all the "official distributors" (emule, and so on ), but no luck, it's probably too much specialized for someone have it to share (but,maybe, now that the video is on youtube ..... )
btw, something similar (but i still don't know if was the same or from different authors, sorry) was used in some shows for "follow" peoples and objects in realtime, "drawing" around them with a laser when they was passing in the sensor field ..... i also seen in the past some vids, but actually i'm unable to find them back, sorry.