iPhone down under - carriers must unlock for free!!
As a UK ex-pat there is one thing you gotta love about Australia, (apart from the sunshine and winding up the locals about the cricket) - the anti monopoly laws.
I have a nice shiny new contract iPhone and on the day I took out the contract I requested that it be unlocked so I can use a travel SIM for when I am abroad or back in the UK. This involved a ten min phone call from the phone shop (Optus) who put me through to iPhone support. They then registered it with Apple and that was it.
An hour later I got an SMS saying my unlock request had been completed. One iTunes sync later and hey presto - one unlocked iPhone thats only 2 hours old :o)