A bar stool, a microphone and a can of Diet Pepsi -- that's all Paula Poundstone needs to make an audience laugh until it hurts. Poundstone, one of the country's foremost humorists and stand-up comedians, takes the stage for one show this Saturday night at Yountville's Lincoln Theater.

The 46-year-old native of Sudbury, Mass., is also a published author and national radio personality but the title that she prefers is a simple one that says a lot: "Stand-up Comic-Mother-Writer." Poundstone's ability to improvise and create humor on the spot is legendary. In her one-of-a-kind two-hour shows, she improvises with a crowd like a jazz musician. She'll find an audience member who sells grass seed to golf courses in part of the state of Maryland and wonder, "In such a small territory, even if the grass seed were any good at all, how could you possibly be working to your full potential?" She is known to be so quick and unassuming that audience members leave complaining that their cheeks hurt from laughter and debating whether the random audience members she talked to were really "plants."

A single working mother, with children ages 14, 11 and 7, Poundstone derives much of her material from her home in Santa Monica, also inhabited by nine cats, a cat-eating dog, a bearded dragon lizard, an elderly bunny and one determined ant left over from an ant farm.

"I love doing my job," Poundstone said. "It's a privilege to perform for people who come to see me and I would do it if there were only six, although I'd have to up the ticket price."

Neve defined by the usual gender-biased topics of relationships, diets, men or sex, Poundstone nimbly mixes in everything that's on her mind at that moment: the shameful deterioration of the broadcast news industry, an argument over a parking space at the museum of tolerance, the irony of recycling her newspaper with a cover story on an oil spill, her near-death experience with cinnamon and the frustration of living in a house full of pencils with no erasers. "How can an eraser that small possibly eradicate all of the mistakes one could make with all of that lead?"

Poundstone began performing at open-mic nights in 1979 and rose to prominence during the comedy craze of the 1980s. She credits her kindergarten teacher, Mrs. Bump, with her success: "She expressed an adult interest instead of squelching my sense of humor."

In 1992 Poundstone was the first woman to win a Cable ACE Award her HBO special "Cats, Cops, and Stuff." In 1996 she debuted her second HBO stand-up special, "Paula Poundstone Goes to Harvard," the only time the university allowed its name to be used in the title of a television show.

Poundstone was the first woman invited to headline the White House Correspondents Dinner, and she provided memorable live coverage of the 1992 political conventions and presidential inauguration for "The Tonight Show." Her casual air and razor-sharp wit made her a perfect fit as backstage commentator for the 1993 Emmy Awards the following year.

She performed at both "A Gala for the President at Ford's Theatre" television specials broadcast on ABC during President Clinton's administrations.

Additional credits include appearances on "Late Night with David Letterman," "The Tonight Show," Garrison Keillor's "A Prairie Home Companion" and "The Rosie O'Donnell Show." Her field pieces on the series "Life & Times" for PBS station KCET won Poundstone a local Emmy Award.

Tickets to Paula Poundstone are available at the Lincoln Theater Box Office, 100 California Drive, Yountville, by calling 944-1300 or by going to www.lincolntheater.org.