NBC Olympics host Bob Costas is about to turn 58, yet his face is as smooth as an ice rink that has just had the Zamboni machine run over it. Even watching in hi-def, he is without a line or wrinkle, a sag, or a bag. It’s hard to keep focused while watching “sliding sports,” so I admit my mind wanders to how Bob Costas manages to look 20 years younger than he is. Is it a facelift, laser treatment, Botox, filler? All of the above? Bob, no one cares about curling, we just want to know how you do it.