Bringing this up with your local AT&T rep is liable to get you laughed out of the store, but things are a little different up in Canada where one of the major carriers is now offering an unlock service -- for a fee. If you're on Rogers (or its budget subsidiary, Fido) and you're a customer in good standing with an iPhone that you've previously purchased from them and you're not currently in a contract, you can pay $50 Canadian -- that's $50 US, for those of you not up to speed on current conversion rates -- to have Rogers' customer service reps flip a switch that'll cause the phone to magically unlock the next time you restore it while connected to iTunes. Considering the restrictions, they should probably be offering the service for free, but it's a start.