You know a salsa club is authentic when the owner’s name is (wait for it…) Roger Rumba. You also know it’s a sweet spot when there are more people busting a sweat dancing than busting out their BlackBerrys. Honduras-born Rumba’s song-and-strut night at Saturday-only club Mambo Lounge (17 SE 8th Ave., Suite B, 314-2639)—upstairs from Imago Theatre—has been on its feet for only a few months now, but it’s already arrived. Attracting hot regional talent—from live salsa bands to local DJs, including Rumba himself—and floor-packing crowds, this nonsmoking joint even offers pre-show lessons for the newbs. On a recent Saturday, Cuban salsa combo Caña Son wailed out emphatic grooves while a mishmash of couples snapped together and apart in rapidfire combination. Yeah, Mambo Lounge is far from glamorous at this point—bare walls, cloth-covered round tables, beer and wine only—but with energy like this, who cares? We came to dance!