Is iphone prepay really a good idea?

It could be a good option if you don't want to pay a monthly fee (I think the iPhone's plans start at $60 a month?) I've been using a prepaid cell phone for years and wouldn't consider getting a regular cell phone a plan... I don't use the phone enough to justify paying $50 or $60 or even $30 a month. With a prepaid plan, I only pay for the minutes I use. I'm not interested in an iPhone, but if I did get one, I'd try to go prepaid. Though I though AT&T wasn't offering a prepaid option with the iPhone.