Before the HBO series Sex and the City began its six-year run in 1998, the world had suspected that women were enjoying guilt-free sex (sometimes when they had work the next morning, too). But until the show came along, this idea had never been expressed in such an unapologetic tenor on mainstream television. It made you want to travel back to 1977, to find Diane Keaton dragging her sorry self around the singles joints of that earlier, grimier New York in Looking for Mr Goodbar, and tell her: "It doesn't have to be like this" - possibly before addressing her as "girlfriend".
The frothy newspaper columnist Carrie Bradshaw (Sarah Jessica Parker) and her friends - Samantha the hedonist (Kim Cattrall), Miranda the miseryguts (Cynthia Nixon) and Charlotte (Kristin Davis), who wears a gaping smile seen predominantly on lobotomy wards - raked over their chaotic love lives, treating with ribaldry those subjects usually only aired in sombre tones on This Morning. The logistics of converting to Judaism could be found in the same episode as discussions about the various flavours of semen. (I'd like to see Fern and Phillip tackle that one. Perhaps they could do a Pepsi Challenge.)
In the final season, Samantha reassured Carrie, who was fretting about uprooting to Paris: "Your fabulousness will translate." But the question facing Michael Patrick King, who has overseen the film version, is how the material will handle the shift to cinema, which demands a more extreme adjustment even than a move from New York to Paris. King has come up with a novel solution: do nothing. The picture is nearly two and a half hours long, but everything about the series is intact - disastrously so. The photography is flat, the editing rudimentary and the structure bitty and episodic in a way that never mattered in bite-sized 30-minute segments, but completely wrecks this big-screen equivalent.
Carrie is now the author of three bestsellers (with raised, gold-embossed lettering on the covers, I'll wager), and is preparing to wed her on-off boyfriend Mr Big (Chris Noth). I couldn't help but wonder when we would get to hear her immortal catchphrase - "I couldn't help but wonder . . ." - but, scandalously, she doesn't say it until the final scene. Luckily we still see her tapping ponderously at her laptop - head tilted at 45 degrees, tongue lolling between her lips, vacant eyes suggesting she's recently suffered an aneurysm.
Meanwhile, Samantha is going stir-crazy in Los Angeles with her actor boyfriend Smith Jerrod (Jason Lewis). Carrie has a new PA, Louise (Jennifer Hudson), and there are various toddlers who belong ostensibly to Miseryguts and Lobotomy Woman, but who receive less affection from them than the brands and logos paraded in front of the camera. I wouldn't say the film's product placement is excessive, but the only store that doesn't appear to have bought itself an adoring close-up is Mister Byrite, where my mum used to send me for cut-price Farahs. I'm not against product placement per se, but even the best-written heart-to-heart scene can only be undermined when you can tell it's choreographed to show everything from Pret A Manger sarnies to Manolo bloody Blahniks in the most flattering light.
The film could have been witty about this, but its tone of gormless materialism remains as unironic as it is unwavering. Louise receives a Louis Vuitton handbag from Carrie with the breathless gratitude of a transplant patient landing a new kidney; and when Carrie gets a wedding dress in the post from Vivienne Westwood, the rhapsodic music and adoring camerawork suggests that a loved one has been raised from the dead, or a lost child returned home. In the middle of a credit crunch, this feels less like sugary escapism than salt poured on a large wound.
But, as with the TV series, there's always Kim Cattrall to temper the pain. With her cutting gibes and those legs like scissors, she could have waltzed straight out of a Preston Sturges film. Long after this unnecessary picture has hit the bargain bins, grown adults will be smiling fondly at the thought of Cattrall in a floppy sun hat the size of a manta ray, or wearing nothing but strategically positioned sushi.