yup prepaid runs the same service provider but with out a contract...nothing there to bind you to anything, just buy the phone then buy the air time card and your set.
ups:
no contract
you can purchase any mintue card(s) you want ranging from 10 to i think 1000 minutes.
i think you can still put insurance on the phone, i don't see why they shouldn't.
downs:
no unlimited data plans to surf the net ETC.
when you buy a download (ringtones,game,application ETC) they take it off your minutes.
since you can upgrade your phone at anytime, sadly to say you must pay the full price of the unit.iphone 3g & 3gs are not included in the prepaid though i think some blackberries might be.