It's always nice to see Flash used in creative ways. It has the potential to be so much more than an advert banner, or an ill-conceived splash page, but people rarely have the inspiration or inclination to push the boundaries.
This site's worth a look. It's just a personal website, but it belongs to a flash developer & video producer, and it's pretty clever:
www.phatterism.com
Seeing it just now reminded me of Little Howard, a Flash-based cartoon character that I've seen a few times at the Edinburgh Festival, alongside his human side-kick, Big Howard. Their site is different, yet kind-of similar:
www.littlehoward.co.uk
Finally, this one's quite old now, but still amusing. Try to ignore the fact that it's a devious promotional gimmick for a large burger chain, and crack on with giving the chicken some instructions to see what you can make him do...!
www.subservientchicken.com