powered not by gravity, but by solar,
looks nice, good desktop toy,
Just saw this on Ebay USA.
Might be good for modifaction for a real gravity wheel...
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270004169189 (http://partners.webmasterplan.com/click.asp?ref=284148&site=1382&subid=&type=text&tnb=32&diurl=http%3A%2F%2Fadfarm.mediaplex.com%2Fad%2Fck%2F707-3922-3266-17%3Fmpro%3Dhttp%253A%252F%252Fcgi.ebay.com%252Fws%252FeBayISAPI.dll%253FViewItem%2526item%253D270004169189)