I can't really describe this, you'll just have to play the video.
(, Thu 30 Oct 2008, 10:46, Reply)
maybe? or string and pulleys...
or magic dust...
(, Thu 30 Oct 2008, 11:18, Reply)
I'm guessing it's a much higher tech version of this:
www.thenakedscientists.com/HTML/content/kitchenscience/exp/levitating-plastic-bags/
(, Thu 30 Oct 2008, 14:08, Reply)