iPhone 4s

[builder22]

been offered an iPhone 4s for 150, it's my mates who had it on a vodaphone contract.
I currently use a PAYG O2 sim but was considering moving to pay monthly if I'm able to keep my number

how much hassle/expense would it be to get the phone working with my o2 sim ?

 

[builder22]

that's helpful yeah, thanks

just reading this... http://ipod.about.com/od/beforeyoubuy/a/Which-Iphone-Model-Should-You-Buy.htm says iphone 4s is only available in 8gb model, is that just wrong? one I'm thining of buying is 32gb 4s, or at least my mate thinks it is!

 

[builder22]

does he just ask vodaphone to unlock it to O2 or will he need any details of mine?
just want to know what details he needs so I can ask him to do it before I get it