How to unlock my iphone 4? Please need your

I need your help…
i have iphone 4 locked by o2 uk and not able to unlock it…
please tell me a method that is free…
and if there's no way so please tell me can i then use it as an ipod
i mean do anything but leaving phone calles, texts etc… Like an ipod…
please help me…
it would be very graetfull on your behalf…

Plug your iphone into the computer and go to the start button and go to my computer then go to your iphone and click on it then where it says _locked type _unlocked

Hi free unlock service is not available for your iphone4.So better you can go for paid unlocking service. If you need to unlock your iphone4 you can visit this site http://www.SuperUnlockCodes.com/apple-aiphone-4/rs1wp9/ get the remote unlocking service and unlock your iphone4 easily.