In the least predictable recent news since Cher announced this year's farewell tour wouldn't be her last, there is word a sex video featuring Britney Spears and her unemployed husband Kevin Federline may have gone missing from the couple's new marital home.

Right now, somewhere in Los Angeles, a young male is freeze-framing a slack-jawed, pool table-mounted Britney for the 327th time and thinking: this is my ticket out of the removals business.

Celebrity sex tapes. On the one hand, they're that little bit of extra access for the 21st-century fan. On the other, they're raising a whole generation of stalkers too lazy to do their own fantasising.

In days of yore, a chap wondering what it would be like to have sex with Abi Titmuss would have to use his imagination to get himself to that point where he decides to break into her home and take her hostage.

These days, all he'd need is an internet download and the ability to tolerate Abi's legendary running commentary.

First seen in stills in the News of the World, Abi's taped threesome with former boyfriend John Leslie and a mystery woman is essentially a pedestrian work, elevated into a classic by the erstwhile nurse's gloss on the action.

Frankly, you don't know the meaning of the word romance till you've seen a coke-eyed, flat-voiced Abi gaze into the camera with the words "John? John, she's licking ..."

Well never mind what she's doing. For our purposes, she's getting Abi a £150,000-a-year job presenting the Fantasy Channel.

Pamela Anderson and Tommy Lee's honeymoon video may have been a small step for them, but it marked a giant leap in humankind's noble quest for knowledge.

Specifically, knowledge about what celebrities look like when they're having sex. Now, barely a quarter goes by without someone's special moment mysteriously being made public - and the benefits are undeniable.

Consider One Night In Paris, the movingly titled film created by a fomer boyfriend of heiress Paris Hilton, which hit the shelves just as her reality show The Simple Life launched, and sent viewing figures sky high. One person's badly lit amateur porn is another's showreel.

However, any celebrity contemplating taking part in a sex tape is reminded that there is a definite set of rules.

First, you need to be in a certain "place" in your career. Namely, tanking. Put it this way, you don't see any Brad Pitt sex tapes out there. (You won't see any Tom Cruise and Katie Holmes ones either, for different but obvious reasons.)

Next, submit to bad lighting, and make sure you adopt several uncomfortable-looking positions during the course of the shoot. This is a humanising exercise. Seeing you all awkward and arrhythmic makes us feel better about our ugly, meaningless lives.

When you've finished, on no account put the footage anywhere secure. Remember, you need to get this thing stolen.

Decorators are a popular choice, but you may want to mark it with a label reading "my private sex tape, do not touch" just to help things along.

And when the tape hits the news, accuse everyone of betraying you. So what if it was you who sent it out? Non-celebrities are stupid, and will never cotton on.

The crucial thing here, if you haven't already, is to split up with the other person featured in the work. Staying together is unthinkably tacky.

No one wants to see a sequel; no one wants to see you two working at your relationship. They want to see you weeping fat tears on a primetime TV interview and talking about feeling violated. And about your new show. Because you'll definitely have one by then.

Marina Hyde @ Guardian