Updated: October 2014
We live in a celebrity culture. There's no doubt about it.
Andy Warhol predicted it with his 1968 quote that "In the future
Since then the collector market for contemporary celebrity autographs has grown accordingly, as demand far outstrips supply.
Collecting autographs is a market that has been predominately based in the US, Canada and the UK but that's now changing.
The rare autograph market is now serious business in emerging economies as levels of disposable income rise, and the search for trophy-assets begins.
After all, what's better than investing in a piece of memorabilia you can feel passionate about?
Top 10 most valuable living autographs
All figures taken from the PFC40 Autograph Index and refer to signed photos unless otherwise stated.
10. Pope Francis - £150 ($242)
Up 20% from £125 ($201) in 2013 - a sign of his growing popularity around the globe.
9. Barack Obama - £350 ($565)
In contrast, Vladimir Putin signed photos are worth £100 ($161).
8. Prince Harry (album page) - £500 ($806)
Up 11.1% from £450 ($726) a year earlier.
7. Madonna - £995 ($1,629)
The Queen of Pop performs to sell out crowds around the world. Madonna is listed by the Guinness Book of Records as the most successful female recording artist of all time.
Her autograph has grown in value by 7.2% per annum since 2000.
6. Ringo Starr - £1,250 ($2,020)
The much-loved drummer's autograph remains the most inexpensive of the four Beatles, yet is rising at a rapid pace, climbing by 14.2% a year since 2000.
5. JK Rowling - £1,950 ($3,150) (signed book)
In 2009,set an auction room alight.
The auctioneer commented: "It's a chair you would normally pay a tenner for in a junk shop", yet it sold for £20,000 ($30,000).
The reason? It was the chair JK Rowling sat in to write the first Harry Potter book in front of her typewriter.
With over_400_million book sales of the Harry Potter series, Rowling's signature is one of the most sought after in the world. She lives a fairly reclusive lifestyle in a Scottish castle.
4. Muhammad Ali - £1,750 ($2,825)
The King of the Ring needs no introduction. A three time world champion, he is considered one of the greatest heavyweights of all time.
His earlier signings as Cassius Clay are even more sought than "Ali" autographed pieces, with a scarce letter written on August 1, 1960 ("I am here at Fort Dix getting ready for Rome, I am in the best of shape... still hitting hard") recently selling for $17,925.
3. Paul McCartney - £2,500 ($4,030)
The Beatles' Paul McCartney is another musician with a huge fan base. His song Yesterday is the most covered song in history.
His autograph has grown by 20.9% per annum since 2000.
2. Prince William - £2,250 ($5,285) (album page)
Rare and in high demand - the perfect combination for producing a valuable autograph. Members of the royal family rarely sign autographs, while Prince William's popularity is soaring following his marriage to Kate Middleton and the birth of their child, Prince George.
1. Fidel Castro - £3,750 ($6,050)
Following the death of Nelson Mandela in 2013, Fidel Castro is now the world's most valuable living signer. Castro's divisive nature and importance to 20th century history ensure there are many suitors for his elusive autograph.
Paul Fraser, founder of Paul Fraser Collectibles, comments: "Getting close enough to Fidel Castro to get an autograph has been impossible since the early 60s - making them extremely rare today. What's more, Castro's signature appeals to collectors who adore and deplore him alike - ensuring those rare examples that do appear for sale achieve big prices.
"Obtaining Barack Obama or Vladimir Putin's autograph is also near to impossible due to the close security surrounding them. Written requests also tend to fail - both have more important things to do. Obama's greater value reveals his global popularity - something that cannot be said for Putin.
"Pope Francis continues to gain admirers both within the Catholic Church and without. It's why his signature has grown by 20% in value since 2013.
"On the royal front, it's fascinating that Prince William's signature is three times more valuable than his younger brother. That's evidence of the extra cachet of the future king. Both signatures are rare - royals generally don't sign autographs."
- Learn more about the benefits of owning autographs. Sign up for your