Guest in show: Why star cameos are a mixed blessing

Rumours that Mel Gibson may make an appearance in 'Mad Men' have appalled devotees of the hit series – including Gerard Gilbert

The internet has been awash with rumours and counter-rumours that Mel Gibson is angling for a part in every thinking person's favourite TV show, the Sixties ad-men saga Mad Men. The Australian actor has reportedly been in talks with the show's creator, Matthew Weiner, about a cameo in the fifth season of the cult hit, which is broadcast in Britain on BBC4.

Given the web-based source of these stories, we should take them less with a pinch of salt and more with the contents of the Dead Sea. AMC, the studio behind Mad Men, has poured water on the claims .

Gibson has pedigree – he played an ad executive in the 2000 romantic comedy, What Women Want – and a role in Mad Men would be a coup for faded star beset in recent years by scandal and marital strife. Whether or not he does turn up on Madison Avenue any time soon, the almost universally negative reaction to the rumours among the shows devotees have highlighted the growing and often fraught phenomenon of the celebrity cameo.

"Putting famous faces into TV shows is an art," said Radio Times editor Ben Preston. "In an age of celebrity the appeal to executives is clear but you've got to get the right person for the right show. Casting Victoria Beckham in Ugly Betty accords perfectly with its trashy, arch, kitsch, values at a time when people are interested in her. But if you get the timing wrong it falls apart.

"Mad Men is so beautifully and meticulously put together that having Mel Gibson launching into the Martini set really wouldn't cut it. But casting Mad Men's Jon Hamm in 30 Rock, for example, is a perfect example of celebrity synergy."

Genre classics like ER or the various CSIs were, and are, replete with guest stars, and even great shows like The West Wing and The Sopranos had their fair share – and a guest appearance byGibson could fairly be considered a coup for any of these. But for Mad Men? In my view it would be an unmitigated disaster – a fatal lapse in taste and artistic integrity from Weiner, a man who, in nearly four seasons has yet to put a foot wrong. The introduction of Gibson, or any other well-known face for that matter, would instantly shatter the lost world that Weiner has so lovingly reassembled.

For Mad Men is less a TV show and more (dare we say it?) a work of art, and Weiner's acute sensibility is leading viewers through that great period of social change, the late Fifties and early Sixties. I'm hoping the story will continue until Watergate – or least to Woodstock. Will Don Draper eventually turn on, tune in and drop out? It wouldn't entirely surprise me. But Mad Men won't be going anywhere once it starts introducing guest stars.

To begin with, the show has its own wonderful cast. In a way, Mad Men might even turn out to be a double-edged sword for the likes of Jon Hamm, January Jones and Christina Hendricks. Where else are they going to find roles as fulfilling as Don, Betty, and Joan? Where else can they be deployed with such precision? Will there, in years to come, be talk of "the curse of Mad Men"?

Either TV shows are built to accommodate guest stars, like The Larry Sanders Show or its contemporary equivalent, 30 Rock, or they attract them once they achieve a certain level of success. In the case of Mad Men, it would be a sign that, tragically, Weiner is losing his marbles. Having said that, you could see why Gibson might be attracted to Mad Men. Many movie talents of a certain age have had their eyes opened to the revolution happening on American cable television drama and comedy, and that the best writers and directors are increasingly gravitating towards the medium, including Martin Scorsese (Boardwalk Empire) and Dustin Hoffman, who next year makes his TV debut in David Milch's gambler saga Luck.

On a deeper psychological level, you also see why the world of Mad Men might possibly appeal to Gibson. Here, after all, is an era when America has had its only Catholic president, when its working culture was steeped in booze, when drink-driving was quite habitual, and anti-Semitic outbursts weren't frowned on in polite society. And the Lethal Weapon star's career has been dogged by allegations of homophobia, sexism and racism – most recently this summer when a tape was released of Gibson purportedly engaged on a racist and misogynist rant against his former partner, the Russian singer Oksana Grigorieva, who has also alleged that Gibson punched her.

But if (and obviously it's a big 'if') Gibson does connect with the behaviour exhibited in and around Sterling Cooper Draper Pryce, then maybe he's missing the central drift of the show – that times they are a-changin'. In the meantime, fans can rest easy in the knowledge that, for the time being, Mad Men will remain unsullied by celebrity.

The good: The stars who shone...

Sir Ian McKellen, Coronation Street

The thesp said his two remaining ambitions were to play a panto dame and to appear on Corrie – the latter wish came true in 2005, when he was well received as an author.

Thomas Pynchon, The Simpsons

In 2004, the reclusive author broke 40 years of silence to appear in The Simpsons. Asked to provide some blurb for Marge's novel, Pynchon said he "loves this book almost as much as he loves cameras".

Victoria Beckham, Ugly Betty

Posh proved she can do more than – to quote waspish magazine editor Wilhelmina – "posing and waving" as she turned up in a wedding scene.

Roy Chubby Brown, The League of Gentlemen

The politically incorrect stand-up comedian played the mayor of Royston Vasey. Bizarrely brilliant.

Johnny Cash, Columbo

In 1974 the country legend played a gospel crusader who murders his wife. He played the part with gusto.

The bad: Those who bombed

Boris Johnson, EastEnders

Looking like a dead trout after a visit to the taxidermist, the London Mayor ("Oh please – call me Boris") glad-hands the locals in the Queen Vic and charms an initially belligerent Peggy Mitchell.

Brad Pitt, Friends

The leading man was nominated for an Emmy for his 2001 guest role although it's hard to see why. His character did little except annoy hermaphrodites.

Geri Halliwell, Sex and the City

The former Spice Girl comes up to Kim Cattrall's midriff as the two – playing old friends – bump into each other in a 2003 episode. Geri's performance is painfully stilted and mercifully brief.

Britney Spears, Will & Grace

She came on like a Deep South Sarah Palin, hamming it up as a Christian conservative foisted on to Jack's TV show, but was outclassed in the camp stakes by Sean Hayes's Jack.

Andy Warhol, Love Boat

The artist owned up to fluffing his line after he appeared on the cruise ship soap in 1985. But why did he ever agree to appear in the first place?