I hope no one faints, but I'm going to disagree with mikedt!

I just don't see how a phone I pay for can belong to anyone but me, regardless of its heavily discounted price. The heavily discounted price is an enticement from the carrier to get me to extend [or, for a new customer, initiate] a contract for
service from them, not for the
phone, per se.
I've never leased a vehicle [I BUY them--I like knowing they're mine!], but I see no analogy here at all. Again, with phones it's the service contract the company is really selling the customer, not the phone. With a car loan or lease, it's the car itself that's being sold to the customer, not a service.
I know from experience that upgrading a phone via my carrier yields me a new phone, which is mine outright, plus a contract I agree to for phone service. I've never broken said contract
*, but even if I did the phone would still be mine because that was our agreement; I would, however, still be responsible for paying for the service contract, whether I'm using said service or not.
* I've been with AT&T so long that I've watched it go from AT&T to Cingular and back to AT&T! I don't break contracts.