Hi [B][COLOR=#455b64]wholebean[/COLOR][/B],
For unlocking no need to go to phone shop directly.You can unlock your iphone3 from home with a help of any one of the online unlocking service provider like MobileUnlockSolutions.com Here you can unlock your iPhone by Remote unlocking method.It's one of the best and safe way to unlock your iPhone without jailbreaking.I hope it will be very useful to you.