KT: You can now connect to 4G networks with your iPhone 4. There are two requirements as of now. First, you need to be in South Korea. Second, you need to pick up a sleeve for your iPhone 4 called Egg. The KWF-B2500 is the world’s first WiMAX (called WiBro in South Korea) sleeve for the iPhone 4 letting you connect to 4G networks for five hours at a time. Sweet.