If you're feeling too detached from the experience of headshotting anonymous competitor's via standard mouse, maybe Zalman's FPS Gun (FG-1000) is what you're looking for. On display at CES 2008, the FPS Gun by Zalman—winner of our Least Worst 3D Gaming Display Award—was impressive in its ability to not be as bad as expected. Perhaps it's that the wrist is positioned vertically, allowing for a wider range of motion that made playing Unreal Tournament 2004 that much more enjoyable.
On the downside, only two of the four buttons felt like they were naturally positioned, with the glowing mousewheel awkwardly out of reach. Perhaps smaller hands will have an easier time scrolling, but when you've got dainty digits like I do, it's hard to imagine the current form factor working for a wide range of players.
Verdict: A good gimmick that works for simple shooters, but not for those in need of a robust button set up.