It's been almost a year since Martin Creed's exhibit at the Nasher closed, but we're still talking about it, because we miss it so. It was a giant room filled from floor to ceiling with some 9,000 yellow balloons, and you could run around through them. Technically, the piece was called "Work No. 1190: Half the air in a given space." What did it mean? Damned if Martin Creed knew. "I'm not a conceptual artist," he told an interviewer just before the show opened. "I don't believe in conceptual art." The balloon room was nothing less than a giddy, transcendent experience: the noise of the balloons like waves, the sensation of kicking them aside to walk, the gold color filling your field of vision as you tried to find your way forward. Please come back, Mr. Creed. Bring more balloons.