ArrowForester
WKR
Get up and go to the bathroom. Then slip the waitress your card. End of debate. Tell your buddies to get the tip.
I, and others in the group, have used this tactic multiple times. We're onto each other now and it's hard to get away with it. And all of this pay-at-the-pump gas makes it a race to the card slot at times. Maybe we should build a kitty beforehand like rayporter suggests.