We're all crazy about collecting

Sci fi fans, comic book addicts and film geeks from across the UK are flocking to the unlikely temple of Milton Keynes's Dons Stadium this weekend to worship at the altar of memorabilia. "Collectormania", which runs until tomorrow, is the latest and largest manifestation of fans' growing obsession with memorabilia which is now driving a global market worth an estimated $4bn (£2.4bn) a year. Punters get in free, but can expect to pay up to £25 for actors such as Gates McFadden (aka Dr Beverly Crusher of Star Trek: The Next Generation) to add value to their figurines with a signature.

Now that even a humble Dalek from Dr Who can fetch more than £20,000 at auction, holding on to memorabilia is no longer dismissed as hoarding worthless junk.

Denise Burrows, managing editor of Collectors Gazette, said: "Programmes like Cash in the Attic have brought collecting to the fore, and people are buying things more as an investment or even as an alternative pension. People still collect for enjoyment, but I think now they have in their mind 'is this going to go up in value?' The auction houses have seen a real upturn because of people wanting to invest in the right collectable models."

As quirky collections are becoming serious assets, there are now some big names getting into the scene. The Independent on Sunday looks at some of the stranger collections of the rich and famous...

Nicolas Cage

Comic collector

Cage is such a comics fan that he took his professional name from Marvel hero Luke Cage (the actor's real surname is Coppola; his uncle is Francis Ford Coppola). Cage amassed an impressive collection over the years, but in October 2002, he auctioned off most of it for combined proceeds of over $1.68m (£1m) through Heritage Auctions. Cage's copy of a comic which features the inaugural appearance of Batman's sidekick Robin went for nearly $132,250 (£80,141).

Jonathan Ross

Comic and film memorabilia fanatic

Ross's collection of film and comic memorabilia is said to be extensive and valuable. In 2009 he donated to charity his copy of the 1962 Marvel comic in which Spider-Man made his debut. The copy, worth at least £40,000, was auctioned for Comic Relief.

Quentin Tarantino

Board games

The man behind Pulp Fiction and Reservoir Dogs can be found hoarding board games when he's not making bloodthirsty cult classics. He is particularly fond of games relating to old TV shows, including The A-Team, and his favourite, The Dukes of Hazzard.

Tony Blair

Collects rare coins

Apparently he took a set of Russian coins he received from Vladimir Putin when he left No10. Chard Coins, the UK's leading coin and bullion dealer, said: "UK Prime Minister Tony Blair received a set of Russian coins, valued at £200, which was one of the few gifts which he kept personally."

Sir Michael Caine

Collects art

An avid art hoarder. His collection includes Galle glass vases and an extensive portfolio of art deco and art nouveau pieces, including works by Galle, Daum, Tiffany, Lalique, Mucha and Erte. Caine had to auction much of it off in 1996 when he and his wife sold their other home in LA, and didn't have enough space for all their art in their UK home. The items were auctioned through Sotheby's with an estimated value of over £500,000.

Judi Dench

Teddy bears

Dame Judi reportedly has more than 100 of them. Elvis and John Betjeman also collected teddy bears, and even Margaret Thatcher is said to have dabbled in the hobby.

Tom Hanks

Collects old typewriters

The Oscar winner boasts a haul of more than 150 manual, portable typewriters. "I collect them from the 1930s until they stopped making them," he said. "I just fell in love with them because if you write somebody a note with a typewriter it is as permanent, and will last as long, as though you chiselled it in stone. I've got, like, 150." His hobby has cost him a small fortune in postage: "I bought a $5 (£3) typewriter from Australia that cost me $85 (£51) to ship."

Alexa Chung

Collects 'dead things'

The MTV host claims to pick up stuffed animals wherever she goes, despite being a vegetarian. She said: "[I collect] dead things, but I'm a vegetarian, so it's a bit hard. I got a dead alligator head in New Orleans. I don't mind if I hate the animal." She added: "Alligators and spiders I don't mind being dead."

Ozzy Osbourne

Beatles geek

The singer has a large collection of memorabilia relating to the band. He said: "I wanted to be a Beatle."

Maria Sharapova

Stamp collector

The tennis player started collecting when she was a child and kept it up into adulthood. She said in an interview: "I always try to collect stamps from every place I go." However, she later admitted to regretting her philately habit confession as "everyone started calling me a dork". Her agent banned her from talking about it further as he was worried it would make her look geeky and not fit the image he was trying to build for her.

Sophie Ellis-Bextor

Stamp collector

When asked what prized possession she would grab if she had to abandon her house at a few minutes' notice, Ellis-Bextor said: "I'd save my photographs first, then it would have to be my stamp collection. I know it's not very rock'n'roll, but I've got a big collection."

Demi Moore

Porcelain and antique dolls, vintage clothing

Demi Moore has more than 3,000 dolls, which she insured in 2009 for $2.25m (£1.36m). The actress began collecting rare figurines while she was married to Bruce Willis. Her current husband, Ashton Kutcher, is urging Moore to display them in her own museum, so he doesn't have to look at the collection, which he finds "creepy". He wrote on Twitter: "Spent the day going through wifey's insane doll collection. 3000 contemporary art dolls all staring at U [sic]. I'm gonna have nightmares. I'm trying to convince wifey to open a doll museum. She also has thousands of Barbies and original GI Joes."