Sandra Bullock owes heartfelt thanks to Sally Field. If the latter hadn’t given us the perfectly awful “Beautiful” a few months back (her first directing gig), the producer-star’s new comedy would be the year’s worst picture about beauty pageants. As it is, “Miss Congeniality” is limp and synthetic, but it does generate a few easy laughs and doesn’t have the aura of smug self-importance that Field’s fiasco did. As far as pageant pictures go, however, it’s miles behind Christopher Guest’s hilarious mockumentary “Best in Show.” (The contestants in that flick are dogs, of course, but at least the picture isn’t.)

In the present case, the screenplay by Marc Lawrence, Katie Ford and Caryn Lucas is a one-joke affair that might have been more at home as a made-for-TV movie. Gawky, perpetually disheveled and occasionally insubordinate FBI agent Gracie Hart (Bullock) is enlisted as an entrant in the Miss United States Pageant when it’s concluded that a terrorist attack is likely to occur at the event. Our gal Gracie has to become the glamorous sort of thing who’d be credible in such a guise while acting as point person in the apprehension of the mad bomber. As an afterthought, she’s also finally able to romance fellow agent Eric Matthews (Benjamin Bratt), who’s obviously been sweet on her from the start but only now, as her contact man in the operation, is moved to act on his inclinations.

This is the sort of situation on which obvious jokes can be hung, and they’re strewn throughout the picture, even though director Donald Petrie doesn’t exhibit much pizzazz in punching them across. Bullock puts her slapstick talents to decent use as the klutzy heroine; she stumbles and falls with alarming frequency, but still manages to keep her character more ingratiating than irritating. Bratt proves himself a good sport as her partner, particularly in a couple of scenes in which the stars must engage in protracted wrestling matches or self-defense demonstrations (he always gets the worst of it, needless to say). The beauty contest milieu also allows for the introduction of lots of stock figures: the icily demanding pageant director (Candice Bergen, as brittle as she was as “Murphy Brown”); the dumb-as-a-post host (William Shatner, reprising the self-deprecating pose of his Priceline.com commercials); and a bevy of rivals, including a sweet but simple-minded baton-twirler from Rhode Island (Heather Burns) who becomes Gracie’s best friend among the contestants.

The real saving grace, however, is good old Michael Caine, who once more seems to be appearing in every second or third film released each week, but here is very welcome indeed. He plays Victor Melling, the snide, overbearing (but ultimately softhearted) pageant consultant hired to whip Gracie into shape for her contest performance. Melling has most of the script’s sharpest lines, and Caine delivers them with an impish glee that keeps the movie afloat even when the plot degenerates into a confused hodgepodge toward the close; though Melling is gay, moreover, Caine avoids the swishy stereotyping that could easily have infected the character. The result is hardly of “Pygmalion” quality, but the Hart-Melling interplay is the best part of “Miss Congeniality,” and it seems distinctly ungracious when, in the orgy of self-congratulation that closes the film, Gracie-Bullock doesn’t thank Victor-Caine by name.

A couple of concluding points. Though the picture was partially filmed in San Antonio, where the supposed pageant is set, it doesn’t make very effective use of the beautiful city–a considerable loss visually. And one has to wonder what the FBI will make of a picture that depicts virtually all of its agents as either inept nincompoops or (in the case of Bullock and Bratt’s boss, McDonald, played in overdrawn fashion by Ernie Hudson) loud-mouthed egotists. But whatever their reaction, the paying public’s reception of this amiable but thoroughly uninspired piece of fluff will probably be pretty mild amidst lots of higher-profile holiday fare.