iPhone 5 Uses Nano-SIM. Regular SIM Cards Not Supported!
What's the price of progress, folks? It turns out that the latest iPhone 5 won't support your regular micro-SIM cards. The iPhone 5 will use specially designed nano-sim cards and the company has made it clear that they won't go back. The nano-sim offers several advantages to the design of the phone by occupying lesser space. Plus, it supports the 4G LTE networks.
Earlier, people would just cut out the micro-SIM from the regular SIM cards; but you won't be able to do that. So if you're buying an iPhone in near future; please note that switching over to another phone is going to be very difficult. You've been informed!