How do you import contacts from an iPhone to the sim card?

I got the iPhone 3g in May 2009, and then my dad got the iPhone 3gs. He recently got upgraded to the iPhone 4 and so gave me his old iPhone3gs. I have a new sim card and none of my contacts are on it. I need to know how I get my contacts from the iPhone 3g onto the sim so that i can import them onto the iPhone 3gs. Thanks.|||if your phone is jailbroken , try Simanager from cydia


if not forget the simcard option..just sync your contacts to your yahoo contacts or outlook or somewhere else (hotmail contacts)


and then sync them to your new phone