i had saw all these videos on youtube on rapid fire controllers and modded controllers and they looked pretty cool. i wasn't up for paying up to 150$ for a game. so i made my own with a budget no more like 5 bucks.
if you want i can give youa tutorial on how to do it over xbox live headphones or whatever free of charge.
you'll need a push button, sodder wire, a soddering gun, a power drill for a hole in your controller, and two wires about 2 inches long and 3 inches long (red/black).
but yeah its pretty nice i mess some people up with the g3 in cod4, and the gehwer in cod5