All publicity is good publicity and the rise of "leaked" celebrity sex tapes has certainly extended the fame of media darlings far beyond the allotted 15 minutes.

Katie Price and Dane Bowers, Pamela Anderson and Tommy Lee, Paris Hilton and Rick Salomon and Tulisa and rapper Justin Edwards all faced a trial by media when their amorous antics suddenly materialised in the public domain.

Sometimes, these homemade escapades jeopardized careers.

Chart-topping singer R Kelly faced a protracted legal battle in relation to a video featuring an underage girl and, in the 1980s, actor Rob Lowe's image was badly tarnished after footage surfaced of a sexual dalliance with two women aged 16 and 22.

Lowe subsequently poked fun at himself when he hosted Saturday Night Live and he continues to wedge tongue in cheek with an eye-catching supporting role in Jake Kasdan's potty-mouthed comedy.

Sex Tape is the raunchy tale of a happily married couple, who drunkenly agree to perform every position in The Joy Of Sex on camera for their private delectation.

When they first meet, Jay (Jason Segel) and Annie (Cameron Diaz) cannot keep their hands off each other and enjoy an impressively gymnastic sex life.

Two children later, there are few opportunities for amorous one-on-one time.

With their cherubic offspring (Sebastian Hedges Thomas, Giselle Eisenberg) safely entrusted to grandma (Nancy Lenehan), Annie and Jay excitedly agree to make a sex tape.

Unfortunately, the exhausted husband forgets to erase the video file and it uploads to the cloud and syncs to several iPads, which the couple have given away as presents.

Jay and Annie are horrified when they realise their energetic efforts are available to download to friends, family, the postman and Annie's soon-to-be-boss, Hank (Lowe).

When pals Tess (Ellie Kemper) and Robby (Rob Corddry) learn about the existence of the recording, they are aghast, especially Robby, who cannot believe Jay performed for three hours.

"That's the length of the movie Lincoln!" he gasps enviously.

Time is of the essence and Tess and Robby join Jay and Annie as they race through the night to delete the incriminating video file from the iPads and spare their blushes.

Sex Tape is a tease that fails to arouse belly laughs or a deep emotional connection to the beleaguered characters.

Diaz and Segel, who previously locked horns in saucy comedy Bad Teacher, are an attractive pairing, but the script short-changes them both.

A protracted sequence at Hank's palatial home outstays its welcome, replete with escalating animal cruelty.

Jack Black cameos late in the film as a porn website proprietor and makes the point that Jay and Annie could have resolved the situation with a simple email or telephone call rather than racing around town like lunatics.

A truncated, 20-minute version of Kasdan's film has undeniable appeal.