Can a US iphone (1.1.2 OTB) used on with O2 sim (contract one) without unlocking?

Hello all,

I got an iphone (1.1.2 OTB) from the US and I would like to know if I would be able to use it with my O2 sim when I get back to the UK (with just jailbreak and activation since unlocking is not yet possible). I do have a contract with O2 for the last couple of years.

I know for sure this works for UK iphones as a friend of mine tested this successfully. Before getting various replies let me explain my friend's case. He got a new iphone from the UK (1.1.2 OTB) and he has the exact same contract with O2 like I do. He jailbroke it, activated it and then used his O2 sim. He is now able to make/receive calls/sms etc.

So basically do UK iphones are different from the US ones?

Thank you

Unfortuantely you can't do this - I bought a 1.1.2 OTB back from Chicago 3 weeks ago, jailbroke and tried my missus's o2 contract sim and it doesn't work.

Got hold of a turbosim and now sitting pretty on Orange :D