LOS ANGELES—The Laugh Factory audience† received a surprise Thursday when actor-comedian Denis Leary dropped by to try out material for his upcoming Ford commercial. "I just like to get up there every once and a while, try out a new bit on the F-150's payload capacity, and see what's working, you know?" said Leary, whose unscheduled appearance bumped two struggling comedians from slots booked more than two months ago. "I've got 15 seconds on zero-percent APR financing that I think is going to kill." Leary later dealt with a heckler by showing him one of the company's many J.D. Power and Associates awards.