If you're not worried about your jailbreak, we're assuming you've already installed the iOS 5.1 update that was just released this afternoon. iOS 5.1 adds some great features like Siri support for Japanese users, a new camera app for iPad, and a new camera shortcut.
The new update also adds a 4G indicator to the AT&T version of the iPhone 4S. While it doesn't truly support 4G, AT&T can call the iPhone 4S a 4G device because it supports HSPA+ networks up to 16 megabits per second...