How to unlock brand new iphone 3gs?

A friend gave me his old iphone 3gs (he's with o2) and i just went to the apple store and payed to get it replaced as it's pretty smashed up. I have brought it home with my Vodaphone sim in, and it says 'your sim card is not compatible' and can't access the phone at all. Why? And how do i unlock it!
Any help appreciated, Many thanks x

Getting an iphone 5 32gb Factory Unlocked in $350?

Some guy on OLX is giving an iphone 5 in only $350 will it be original or refurbished? I asked him he said it is original belive on me. But on the official official Apple website there are not that cheap i said to him this too. So he said i have a contact with the apple sales representive so can some one help me about this please it will be a pleasure thank you.

My iphone 5 is glitching out?

Ok so i just got my iphone five yesterday night. I went to go sync music and everything from my computer to the phone. Then like this apple and and empty bar popped up. It hasn't moved for like an hour.

How to update my iphone4 to ios 6 and can still use gevey sim?

My iphone 4 is locked and currently i'm on ios 4.1 and using gevey sim. There are a lot of apps that needs to be updated but i can't since i need to update my iphone's ios first but i'm afraid if i update it i can no longer use gevey sim. What can i do to update my ios and still use gevey sim? Please give me options.

ITunes declined credit card

I have a purchased a few apps on my iphone and I pay for them with PayPal I have spend 4.00 worth of apps and have 4.83 in my account but it hasn't been taking my money out right away and I can't download free apps or nothing because it says my credit card was declined when it activated and I got plenty of money please help!

My iphone 3gs keeps flashing up with the apple logo?

I have an iphone 3gs around 1 and a half years old which keeps flashing up every few seconds with the apple logo, also when I connect the charger the phone will not charge. What can I do for it to work properly again?