I hope this hasn't been posted yet (didn't see it), but here is an interesting article with regards to the iPhone. The author spent 45 minutes playing with it and states that it actually runs Leopard. Lots of other great info in here as well, check it out:
http://www.suntimes.com/technology/ihnatko/215441,CST-FIN-Andy18.article
http://www.suntimes.com/technology/ihnatko/215441,CST-FIN-Andy18.article