"We still make it the way my father taught me," says owner Mario DiPaolo. "Water, lemons, sugar." He swears by Sunkist lemons and Domino's sugar. "I don't use beet sugar.

"I go almost every day to South Water Market to look at the fruit. I don't call on the phone." The stand offers about a dozen flavors -- customers wait anxiously for the appearance of peach each year.

"We just had lemon until the middle '60s," DiPaolo recalls, "then my dad start fooling around with flavors." No matter what flavor it is, they all taste of lemon, since the fruit flavors are all added onto the same lemonade base, complete with rinds and the occasional seed.

"We squeeze the lemons," DiPaolo says. "We juice seven, eight, 10 cases a week.

"There really isn't any secret -- a lot of other people's lemonade doesn't taste as good because they don't use lemons. They use concentrate and all sorts of stuff."

The Italian-lemonade process is much like ice-cream making and uses similar machinery. "Originally we used a machine with rock salt and ice," DiPaolo says. "When I first started, I had a hand crank."

DiPaolo, 50, has spent his lifetime living near the store in the up-again-down-again but currently hot Little Italy neighborhood. He's been selling the frigid concoction since he was 7 or 8 years old. "In the mid-'50s, my dad bought the building," he said. "My dad had a grocery store there," next to where the stand is now. "It wasn't always the booming lemonade stand you see.

"My dad is the one who started the lemonade. We sold lemonade inside the store, outside, everywhere." Eventually DiPaolo's father, also Mario,, built the stand, which at first had no roof. "When it rained, we got wet." Now the stand is almost luxurious, with both a roof and screened windows.

People come long distances to stand in line at Mario's, double-parking on the street. "We really run the gamut of people. It transcends everybody," DiPaolo says. "You can take a ride and spend 80 cents. I go to the show and the candy's $5." Besides lemonade, he also sell candy and nuts.

DiPaolo is at the stand every day. "Me and my mom are still here. We still care about it," says DiPaolo. DiPaolo's mother, Dorothy, still works with him at the stand daily, along with a family friend, Teresa Schrauth, a 14-year employee who's lived in the neighborhood for 75 years and has always helped out at the stand.

"I met my wife (Maria) here," DiPaolo says. "She started working here when she was in high school and one thing led to another and we got married."

DiPaolo hopes his children -- Mario Jr., 9, Davina,6, and Marco, 3 -- will eventually take it over. He's adamant about "not franchising, not opening another one. I just want to keep it to one lemonade stand."

He likes being a landmark, a success. "There really isn't a secret -- it's hard work. It's coming to work when you don't feel like it, when your wife is mad at you, when your kids are bothering you.

"It's a grueling job for the five months we're open," DiPaolo says. In the winter, DiPaolo does odd jobs, tends to property he owns and gets ready for the next summer. The stand, which is open daily from 10 a.m. to midnight, begins its season on May 1 and closes in mid-September.

"I always like to close on a hot day," DiPaolo says.

NEW. Fog City Diner's just blown into town, adjoining the new Hampton Inn and Suites at 33 W. Illinois St., Chicago. The San Francisco-based chain is owned by Northbrook native Bill Higgins, an alumnus of Glenbrook North High School, and his Real American Restaurants partners Cindy Pawlcyn and Bill Upson. The trio met when they all worked at the Pump Room in the 1970s, then went on to found Napa Valley's acclaimed Mustards Grill and host of other West Coast restaurants. Former boss and mentor Richard Melman of Lettuce Entertain You Enterprises has joined them in their Chicago venture....

Bruce Bowers, chef of the Las Vegas Fog City Diner, has come to run the kitchen here. No ordinary diner, fare includes such offerings as red curry mussel stew, roasted garlic custard with sauteed shiitake mushrooms, and roasted sea bass with wilted pea sprouts, but also diner staples like meatloaf (albeit made with veal at $13.95) and milkshakes and malts. We didn't get to sample the lemon brown-sugar meringue pie, but it looked luscious.

The decor is dressed-up diner too, with mahogany-trimmed booths, a marble-topped counter and an open kitchen.

Fog City accepts reservations and is open from 11:30 a.m. to 11 p.m. Sundays through Thursdays, till midnight on weekends. Entree prices range from $11 to $15. Call (312) 828-0404.