My bad...I have Iphone 4 which uses micro sim. But it looks like earlier version of Iphone (3G and 3GS) use normal sim card (also known as mini sim card) as mentioned in this forum. "Specifically, the original iPhone, iPhone 3G and iPhone 3GS use a Mini SIM, more typically called just a SIM card, and the iPhone 4 (GSM) uses a Micro SIM. " (http://www.everyipod.com/iphone-faq/iphone-sim-card-troubleshooting-upgrade-from-original-to-iphone-3g.html)