A group of mine does shows over at the Theater Artaud in the industrial hinterlands of Potrero Hill. We started noticed the lines of the hippest and slickest across the street of this glowing blue orb of a club called Circolo. Eventually we went and checked out the scene, which is when I learned what an "ultralounge" was. Yes, SF has an ultralounge. Here it is. A nite club designed on the tenets of new millennial social engineering, dictating a mood set by lighting, tempo of music, seating, ceilings. In other words, a less obtrusive lounge for better socializing, but still hella trendy and super slick. They do late nite here, so you can stop by after midnight, nibble tasty Asian tapas, and groove to whatever DJ is spinning that night.