hi all..

i need help in buying iphone 3g
i'm totally new in this iphone thing

i'm not from US and my country didn't sold iphone,
luckily my friend planning to go to US this august, and i want iphone 3g so bad
i know i need to unlock it (different from other regular gsm phone)

i want to ask is,
1. after i purchase the iphone, do i need to take the at&t contract and the cancel the contract, or i just buy the phone without buying the contract and unlock it with software from the webiste?

2 is there will be a problem with the unlocked one?

thx before
much appreciate it