When it comes to falling stars, Vegas is one huge meteoric crater. Anything goes in this land of lounge acts. From Peter Noone, the boyish 1960s love idol of Herman's Hermits to Rick Springfield, who hit his zenith in the 1980s (more recently than most entertainers in this town), taking the stage nightly as the hero in MGM's "EFX." But it's the Orleans who grabs them all at some point. The showroom contracts with Jerry Lewis several weeks a year and from then on it's pot luck: David Gates of Bread, Debbie Reynolds, and Eddie Money. If you didn't catch them when they were hot, now you can catch them when they're not and usually for under $35. The Orleans, 4500 W. Tropicana Ave., 702-365-7111.