It's not often you see novelists guest starring on TV shows - particularly novelists who are aged 83 and describe themselves as "cantankerous curmudgeons". Guest-star spots are usually reserved for the perky and hip J-Los of the world; stars who are instantly recognisable to viewers and will help boost ratings. But Gilmore Girls has never been quite like any other US drama, mainly because of its bookish undertone. In Stars Hollow - Lorelai and Rory Gilmore's fictitious hometown - reading the classics is way cool.

Fittingly, in tonight's episode titled Norman Mailer - I'm Pregnant!, the literary legend plays himself and turns up at the Dragonfly Inn with a young reporter (played by Stephen Mailer - real-life son of Norman) and so begins an Algonquin-style soirée. The three key scenes featuring father and son were apparently 95 per cent improvised and involved Mailer Sr talking about what he knows best: writing.

It seems a little odd that a literary heavyweight like Mailer would agree to appear in this upbeat TV mother-daughter-coffee drama. Yet in an interview with newyorkmetro.com, he said he had a soft spot for Gilmore Girls because of his daughter.

"I almost never watch sitcoms... But for some reason I find Gilmore Girls kind of agreeable. The character Lorelai reminds me very much of my second-oldest daughter, Danielle - both of them are like beautiful hummingbirds, constantly talking and adjusting what they say, quick to the breeze. I told her to watch, and she said, 'I watch it all the time'."

It's interesting to note this episode aired in the US in late 2004 during the show's fourth season. Dedicated fans can look forward to another cameo in season six (airing now in the US) when former US secretary of state Madeleine Albright guest stars.

So has there been any guest appearance that can trump Norman Mailer? Possibly not, but the following guest star spots have come close in their quirkiness.

What's kookier than a literary legend turning up in a squeaky-clean American drama? A US presidential hopeful appearing in a sketch comedy show. In 1968, just two months before he was elected president, Richard Nixon appeared on the infamous sketch comedy/stand-up Rowan and Martin's Laugh-In and somewhat nervously uttered the show's famous catchphrase: "Sock it to me."

In 1999 and 2000, famed physicist Professor Stephen Hawking provided the voice for his character in two episodes of The Simpsons. The biggest laughs came as Homer kept referring to Hawking as "Larry Flynt".

A lot of strange things happened on The Love Boat, but none stranger than when Captain Stubbing welcomed passenger and famed pop artist Andy Warhol aboard in 1985.

There was no guest-star casting creepier than when Fonzie turned up as a perverted dentist accused of murder on The Practice in 1999. Henry Winkler's portrayal of the disturbed doctor was so convincing it earned him an Emmy nomination. Fans of "the Fonz" should note he's now starring in the hit US sitcom Out of Practice.