Renee Zellweger, Sarah Paulson and the mummified remains of Tony Randall.

Down With Love is fun and frothy, both a satire of and homage to the wholesomely sexy romantic comedies of the sort that Doris Day and Rock Hudson used to star in. You know the type: cheery paeans to the things one will do to ensnare the opposite sex, full of white lies, bright colors and fast-paced, double-entendre-loaded dialogue.

Or maybe you don't know the type. Hey, it's the 21st century; who could blame you if you've never seen Pillow Talk or Send Me No Flowers or any of the others? But if that's the case, Down With Love may not be for you, or at least you'll miss some of the humor.

The movie is set in 1962, a year that was presumably on the precipice of the sexual revolution. Barbara Novak (Renee Zellweger) has written a book called Down with Love in which she urges women to forsake romance in favor of career, and to enjoy sex the way men do - ala carte, without emotional entanglement. Through the clever promotion of her editor, Vikki (Sarah Paulson), the book becomes a runaway bestseller and soon women the world over are upsetting the social order by looking for jobs and choosing when to have sex. Shame on them!

Who can turn the world on with her smile?

Enter Catcher Block (Ewan McGregor), "ladies' man, man's man, man-about-town," the star investigative reporter for Know magazine. In a move worthy of Rock Hudson, he decides to masquerade as a wholesome astronaut, woo and win Barbara, and show the world that all women really want the same things: love and marriage.

So will these two crazy kids get together? Well, the road to true love is twistier than you might expect, as Barbara lays out in a hilarious monologue, and the ending is much less predictable than one of those old Doris & Rock comedies. The pitch-perfect script by Eve Ahlert and Dennis Drake is cute and clever and extremely funny. They nail the character types, the pacing and the patter, and skewer the whole genre in a very affectionate way, creating a 1960s romantic comedy that gives way to a modern sensibility.

None of which would work if the actors didn't get the joke; thankfully, they do. Zellweger, with her wholesome look and squint-eyed smile, does some delicate maneuvering as Barbara. There are times when she needs to exaggerate the Doris Day-ness of her role, others when she needs to play it straighter, and Zellweger always seems to make the right choice. McGregor is hilarious as Catcher; his timing, his body language and his wolfish grin are dead on. They're admirably supported by Paulson, who inhabits and enlivens her wisecracking-best friend role and David Hyde-Pierce, playing Catch's neurotic, insecure boss and sidekick. (You know, the Tony Randall role.) None of them make the mistake of thinking they're playing realistic characters; it's an over-the-top movie with over-the-top people in it.

David Hyde-Pierce and Ewan McGregor.

It's all pulled together under the able direction of Peyton Reed. Working with costume designer Daniel Orlandi, art director Martin Whist and cinematographer Jeff Cronenweth, he's created an Easter egg-colored world for his characters to inhabit. The obvious sound-staginess of the backdrops, the New York geography that bears no resemblance to real life, the larger-than-life mod-ness of the apartments and offices, are all part of the fun. The sight gags are too numerous to mention, but I particularly liked Barbara and Vikki's contrasting outfits, which they display in model-like poses when they enter a room, and the split-screen telephone conversation that implies a certain naughtiness on the part of our leads. (Hey, they're just working out. I should get my mind out of the gutter.)

So, yeah, I loved it, but I have a fondness for the genre. If you don't, well, I won't hold it against you if you don't take my recommendation on this one. After all, you won't know what you're missing.

Gorilla Pants rating: 3.5 out of 4 bananas