>Virgin Mobile stonewalled me the whole time, told me to take to to Apple.

That's because the physical phone is between you and the manufacturer. That includes the warranty, unless you purchased special insurance through Virgin. I wouldn't expect the carrier to provide you with a new phone. This is all in your contract.

That said, I think the expectation and problems like yours are rampant enough that most carriers are in fact offering some kind of "no hassle replacement" insurance for the handset. As the front line in the cell phone business, the carriers hear it from the customers in cases like these.