SOME stand-up comics will do anything for a laugh. Just ask Katt Williams, who finished a 21/2-hour set at the Laugh Factory in Hollywood Sunday night by opening a cash-filled briefcase and handing out $100 bills to each of the 280 people in the audience. The impromptu handout astonished fans, who applauded wildly. Laugh Factory owner Jamie Masada told us: “I hope people don’t get the wrong idea. We serve comedy every night, not $100 bills.”