The Duchess of Idaho is a lesser Esther Williams vehicle, and while it's certainly painless, it's also a film best appreciated by members of her fan club. Duchess of Idaho finds Williams moving into situation comedy territory, "best friend" division -- meaning that there's a complicated (and fairly far-fetched) plot in which Williams will go through a pointless charade in order to win a man for her roommate and pal. This kind of thing works better on the small screen where it can be condensed into a breezy half-hour; onscreen it takes more precision and invention to pull this thing off for an hour and a half, and the writers fall down on the job here. It's not all their fault, as they have a mandate to find room for a couple of water ballets, a number of irrelevant specialty acts and a bit of Sun Valley scenery, all of which gets in the way of both plot and pacing. Still, those water ballets are certainly something (featuring a bit more "dry land" dancing than is normal) and the cutaway numbers by Lena Horne and Eleanor Powell are keepers. Plus, there's Williams, not a great actress but a pleasant personality, who's fun to be with here and the always entertaining Van Johnson. Duchess is hardly cinematic royalty, but it's genial good fun.