[fpgeek]

You can do that in the US, but it isn't common because of carrier subsidies. Even worse, sometimes when you pay full price for a phone you still wind up with something that is carrier-locked anyway. Plus there are all sorts of technical incompatibilities (e.g. AT&T vs T-Mobile 3G bands) even if your phone is otherwise unlocked. And so on...

[jiggy2011]

Surely when you get a contract for your phone & service you pay X for Y months and this should cover the cost of the phone anyway. So even if you switch the phone to a different carrier you're going to be paying the contract amount anyway.

I could unlock my phone and use a different carrier (considered doing this after the o2 fiasco yesterday) but it wouldn't make economic sense to me.