unlock iphone 4 on orange? (need it done by tomorrow)

[Herr Flick]

as above, im getting an o2 contract and my phone is on orange, its running the 4.2.1 firmware so is it possible to unlock it??
orange can do it for £20 but dont fancy paying that!
most places for 'jailbreaking' say that it can not be unlocked but sites that charge say it can?

thanks

 

[sbridgey]

you can jailbreak it i think to allow you to use any sim but you need to downgrade firmware as i dont think it is possible yet with that version

 

[Revels]

Massive thread on this already.

It's stuck at the top.