iOS (Jailbroken): Apparently, Apple was testing a panorama mode feature for the iOS 5 camera, only to leave it in test mode for the actual release. All you have to do to enable it is to jailbreak your phone (instructions here), then find the Firebreak app in Cydia. Once installed, just follow the on-screen instructions to make a panorama picture.
Keep your expectations in check, however, since Apple probably kept it from the release for a reason.
Hidden iOS 5 Panorama Mode Revealed [MacRumors]