Lil' late to the party but anyway:
I have a Hori EX Pad controller. Essentially I strap a rubber band around the turbo button to press "A" over and over for hours on end. I have a host check map that makes games last around 4-8 seconds long. That's how people have the 100,000 custom games played on Halo 3. Almost all charge, but I don't care as I like high amounts played too. Makes your account look beast.