Ross Ching does a lot of great motion time lapse using stills. You can check them out here:
http://rossching.com/
He also has some behind the scenes footage of how he does it.
I have been playing with a Cannon i720 Powershot with the CHDK firmware. You can see some low quality results here:
http://www.flickr.com/photos/wotipka/2582500660/
kris@wotipka.com
Image maker