If you're *REALLY* into your first person shooters, you may be pretty damn eager to get your mits on this thing. Not sure how good it would actually work in terms of further immersing you into the game, nor how long it would take one to get used to it (though i'd imagine quite a while), but the concept at least seems pretty cool.
Techpowerup have posted up the details on it here.
Berkeley, CA -April 2007 - Good Work Systems today announced the release of the Fragpedal Elite, a sleek new edition of their popular new dual-foot 4-button Fragpedal™ USB gaming foot pedal. The Fragpedal Elite follows in the "foot steps" of the original Fragpedal Classic released in early 2006, this time with a new button design nuanced for ultra-fast "twitch" response in First Person Shooters. Both models of the Fragpedal allow gamers to enter mouse and keyboard commands as well as sophisticated macros with both feet, a capability that has been wholeheartedly welcomed by PC gamers.