Call him what you will-local celebrity, nightclub mogul, friend of Schwimmer, party-circuit staple, publicity hound-pretty much everyone agrees on at least one point: Billy Dec is extremely savvy.

All Dec’d out: Billy Dec, surrounded by models from a recent fashion show, at The Underground; right, a waitress in the club’s “undercover” garb.

Take his latest venture, The Underground (56 W. Illinois St.), which launched with a YouTube campaign directed by David Schwimmer and starring that other celeb pal of Dec’s, Joey Slotnick. We’re not sure if the videos were meant to be ironic (modeled after the current Mac commercials, the spots make fun of “club guys” much like Dec and Co.), but they are entertaining-and buzz-generating. So when the first of several private pre-opening parties was quietly announced the Friday before New Year’s Eve, my curiosity was piqued.

Formerly occupied by Harry’s Velvet Room, the space has been refitted with a spy theme resembling the inside of a bomb shelter. “I got the idea when I used to go to The Underground off Ben Yehuda Street in Jerusalem ten years ago,” Dec’s partner Brad Young told me. “It was this subterranean, divey club that was always packed. If you had to use the bathroom, you’d go to the next-door felafel stand.” Chicago’s version aims for a different vibe; for starters, there are plenty of restrooms. The Underground is comfortable, loungy, industrial, and very exclusive-so much so that Dec discourages the staff from giving out the club’s exact physical address.

Inside, the western wall features an elongated, Lite-Brite–like globe, and a raised DJ booth acts as the room’s centerpiece. Staffers are outfitted in sexy military garb, and libations come with names like Manhattan Project (an $11 mix of Patron Silver, Malibu rum, pineapple juice, and lemon-lime soda “designed to detonate your taste buds”). The food is familiar-with one addition of note. “We serve the number one item purchased in times of disaster, when retreat to a shelter or safe house is most probable: strawberry Pop-Tarts,” Dec says. Some faces are familiar, too. Dec’s longtime pal and business partner Arturo Gomez is also a co-owner.

Expect one other Dec trademark: topnotch service. Thanks to connections cultivated over the years at Solo, Circus, Rockit, and Le Passage, Dec’s crew is adept at attracting celebrities and VIPs. About a week before the pre-opening, I was invited to Rockit to have my picture taken for my very own Underground VIP card, which contains all of my personal preferences-what I like to drink, what music I like to listen to-so that, when I show up  and swipe my card, the staff will know exactly how to cater to me. (For the record, that’s Effen Black Cherry and 7Ups, please, and crank the hip-hop.) Cards are available by invite only, so consider snagging one to be your mission, should you choose to accept it.

Barhopping

Bucktown’s Leopard Lounge has found a new co-owner in Tommy Leone, 35, the guy who brought us Goodbar and Spoon. Expect a total makeover come spring 2007. . . . Speaking of spring redos: the guys behind Reserve are transforming Phil Stefani’s now-defunct L8 into Crescendo, a bi-level, upscale lounge and late-night restaurant. . . . In case you missed it, Sauce is now Krem, a South Beach–style lounge in the heart of Old Town (think The Delano meets Lincoln Park). The stark, all-white interior is outfitted with beds on which to strike poses-or do something naughtier. Co-owner Ben Galatz was formerly a manager at Celebrity in Wicker Park. . . . The original Iggy’s is now Juicy Wine Company-and doesn’t look anything like the space’s former tenant. Dressed in blond wood and cork accents, the upstairs lounge hosts laid-back sippers, and a small retail shop downstairs sells wine. There isn’t an ounce of edge left, but it makes for a cozy date spot with a menu of wines, exotic butters, and cheeses.

Photography: Chris Guillen