This was apparently at SIGGRAPH 08: It's pretty amazing technology, and could be a lot of fun to play with.
Apparently NVidia had them do this stunt at the NVISION show. (From Laughing Squid, forwarded to me by a coworker.)
Emma acquired a flag today at home depot, so I took a video. Lets see what posterous does with it. :-)
Anthony Hamilton.
Edit: apparently, the videos I originally linked to disappeared, and the official videos aren't embeddable (why?!?). So here are some links:
See what I mean? Man's got so much soul, you can smell the chicken and greens when he sings. ;)
This video (and the song) is tight. Props to Garry for turning me on to it.