(FORTUNE Small Business) – >> It's amateur night at Caroline's on Broadway, a legendary New York City comedy club, and David Moore is working the Monday crowd. "I read that some of Enron's former managers posed nude in Playgirl," he says. "Finally, someone at that company made full disclosure. The pity is, all it did was highlight their main problem in bankruptcy: shrinking assets."

The phrase "amateur comedian" usually fills people with dread, but Moore, the chairman and co-founder of Sonostar Ventures, a VC firm, is actually pretty good. He started his hobby three years ago after a colleague told him about an open-mike night, and now he performs his business-related humor about five times a month at clubs in New York, Boston, and Los Angeles. In January 2000 he was named Top Amateur Comedian in Manhattan by Stand Up New York, and last summer he even landed a two-night gig opening for Saturday Night Live's Darrell Hammond.

Of course, compared with what he earns at his day job, the money that Moore, 46, makes telling jokes would barely buy him lunch (the Hammond shows netted him just $25). But it does offer other rewards, like the chance to trade jokes with better-known comics, like SNL alum Colin Quinn, who's become a Moore fan. And he says that the comedy has made him a better boss too. "Humor is an underappreciated management tool," he says. As he tells the audience at Caroline's, "Now that people in my office know that I'm a comedian, they expect me to be funny all the time. But I've learned the hard way that there are some situations where it just doesn't work: 'Hey, did you hear the one about no Christmas bonus?'" --ERIKA RASMUSSON