Left Foot Braking.
i agree with barnoun. left foot braking IS a road racing technique. if any of you watched the Winston Cup race this past weekend at Wakens Glen, you probably saw drivers do this. though i think its' much more common at Sears Point.
double footting increases reaction times, you don't have to wait for you foot to move over. also even at DAYTONA, TALLEDEGA, drives "tap" the brake to slow the car down, but they don't loose momentium. especially needed with those restrictor plate engines.
it has also been used to keep a car in grip comming out of a turn. lightly touch the brakes, depending on car setup and track, can aid in reducing push. on cup cars it helps keep the front nose down to the ground.