One of the items on the long list of unusual things about the iPad is it's weirdly-small SIM card. It seems counterintuitive. It can't be to save space, because the iPad is way bigger than the iPhone and has more than enough room to fit a normal-sized SIM. It seems more likely that Apple gave it a different size for no other reason than to stop iPhone users from plugging the SIM card from their iPhone (or other smartphone—remember, it's unlocked) into the iPad whenever they want to do a little browsing, forcing them to sign up for a new plan.
