i use both feet when using the brake while giving the car gas (ie: when the emergency brake is pulled and i'm doing 30 around a corner //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif )
i COULD do it with one, but i don't feel anywhere near as comfortable with it...
but otherwise... 1 foot... no point in using 2 on an automatic...