WHAT MADE "Saturday Night Live's" Jimmy Fallon so appealing during his stint as "Weekend Update" co-anchor was the genial-goofball, regular-guy persona he affected -- or, rather, didn't affect, since it seemed so natural. With his un-glib delivery and slacker hair in need of a good combing, he came across not like a blow-dried TV personality, but like the smirking drinking buddy from the group house next door. He was always at his best with a quip, or riffing, like some Robin Williams manque (way, way manque), on the cultural zeitgeist.

Unfortunately, what made him great on "SNL" -- the fact that he was no movie star -- makes him a terrible movie star.

His first starring vehicle, "Taxi," goes nowhere fast. Teamed up with Queen Latifah, who plays a daredevil New York cabbie whose vehicle is commandeered by his inept, carless cop, Fallon is hot on the high heels of a quartet of Brazilian supermodel bank robbers (Giselle Bundchen, Ana Cristina de Oliveira, Ingrid Vandebosch and Magali Amadei, playing vapid, angry and beautiful, which is never a good combination). As officer Andy Washburn, Fallon essentially tries the same trick that worked so well for him on TV, which is to say he plays himself. Aside from delivering a few cute bits though -- imitating "The Lord of the Rings' " Gollum, breaking gamely but lamely into Natalie Cole's "This Will Be (An Everlasting Love)" and affecting a heavy Cuban accent during an undercover sting operation -- there's just not enough of "himself" to go around on the big screen. He seems slight, insubstantial, and not just when standing next to his large-and-in-charge co-star.

The movie's heartbeat does pick up a bit when it gets behind the wheel -- Queen Latifah's Belle is a speed demon in her souped-up Crown Vic -- but for a movie called "Taxi," it spends a strangely inordinate amount of time pounding (and pounding) the beat. I never thought I'd say this, but this buddy film could have used a few more car chases and a few less scenes of Belle and Andy saying "trust me" to each other. After Belle's car is impounded as evidence, and whenever the bad girls' candy-apple red BMW is idling at the site of their latest heist, the movie stalls out completely.

Here's the weirdest thing. During the closing credits, director Tim Story runs a bunch of outtakes and bloopers, many of which feature Fallon doing what he does best. In other words, he's seen cracking up his cast mates over and over again, as he does when he jokes, after inhaling nitrous oxide, that his gas-altered voice makes him sound like "Barry White's illegitimate grandson."

It's a shame that the movie, couldn't capture that sense of joyous, on-the-fly wisecracking.

TAXI (PG-13, 97 minutes) -- Contains some obscenity, mild sexual innuendo, shooting and reckless driving. Area theaters.

Even Queen Latifah and Jimmy Fallon can't steer "Taxi" in the right direction.