Funny, it's extremely easy to do outside of US. I can walk into most cell companies up here get a 3 year contract with a new phone, pay some fee ($10-75 or so depending on the carrier) and walk out with a fully unlocked phone on a 3 year contract.

Similar here in the UK. I bought an unlocked Nokia Lumia 710 for £99 new and am on a £20 a month giffgaff pay as you go service. 800 mins to any number, free calls to other giffgaff users, free texts to any network and unlimited data.

It's not easy, nor does it make financial sense. Only one 'major' carrier (T-Mobile, at less than 10% of the market) offers a discount on monthly contracts when you decline the subsidized phone. On AT&T, Sprint, or Verizon, you are throwing away a $300-400 discount that you're paying for anyway.

Only very recently, with Google's $300 Nexus 4 and improving prepaid GSM data plans has it even been feasible to avoid the lock-in when shopping for a smartphone.

Europe, Asia, and the developing world are far ahead of the US in terms of wireless competition.