Gearbox have announced that Duke Nukem Forever will be using Steamworks. Whether you buy the game digitally, or on a disk, your game will have to be tied to a Steam account. Duke Nukem Forever is now available to pre-order from retailers as well. Pre-order bonuses include access to an in-game big head mode, T shirts and a trucker hat. The Balls of Steel edition is also available if you fancy getting your hands on a great big bust of the Duke. The game's due out on May 3.