What happens if you cancel your AT&T plan?

Does anybody know if the iphone would still function as an ipod/ calendar/ photo carrier/ camera/ note taker, etc. (you get the idea) if you shut the phone service off? I'm not ready to try this mind you, although I -have- had more dropped calls in the last week than in months with my previous carrier.

I'm guessing it would probably go into perpetual airplane mode, right?

Has anyone cancelled service and kept the phone for its other features?


~Arn