The cars include John's Rolls Royce Silver Cloud named "Daisy" and an Aston Martin called "The Beast," according Christie's. Passengers of the cars, other than the ostentatious singer, include Sting, Hugh Grant, Gianni Versace and George Michael. Christie's estimates the cars will bring in approximately $1.4 million.

This is just the latest in a quite lengthy string of celebrity auctions to hit the block. A selection of Madonna memorabilia is currently up for sale online through Leland's auction house. Leland's is more noted for its sports collectibles, but has recently gained more exposure and credibility with the entertainment industry.

Leland's auction, only online, also includes Jimi Hendrix's personal stash box, Jim Morrison's humidor, Elton John's Elvis-like jumpsuit and a saxophone signed by former president Bill Clinton and band members of Fleetwood Mac. Sotheby's, not to be outdone, last week sold a bed and underwear belonging to British pop star Robbie Williams, with proceeds going to his charity, Give It Sum. Williams' undies may have been purchased for a cool $3,200, but Madonna's bra-and-panties set is already priced above $8,000 on Leland's Web site.

"Celebrity auctions are very popular," said Christie's spokesperson Patricia Clark, "especially Elton John, who's incredibly popular here in England.

"There is generally more interest in celebrity auctions. People love the idea of owning a bit of a star, a piece of history. It makes their lives a little more interesting."

Marty Appel, spokesperson for Leland's, agrees.

"Buying the items is a connection to someone they appreciate, someone whose performances they've enjoyed," Appel said. "The entertainment items draw a lot of press and attention to the auctions, which contain many, many lots other than those select items."

Sometimes, celebrity castoffs are bought as an investment, Appel said.

" People think they'll be even more valuable in 30 to 40 years," he said. "Madonna figures to be a 'forever' icon. Anything associated with her has value for a long time, as she's become a legitimate Hollywood icon."

Clark and Appel cited increased international interest in entertainment industry items over interest in more mundane pieces. Leland's claims that its "online only" strategy to auctions makes it even easier for the international buyer to bid and purchase an item, by leveling the auction playing field for everyone.

Christie's has held numerous auctions for Hollywood and the entertainment industry, including a James Bond-theme auction - Ursula Andress' famous bikini from Dr. No was sold - and Marilyn Monroe and Princess Diana auctions.

John recently lost a court battle with his former manager and accountant. Christie's, however, insisted that The Rocket Man is selling his cars because he doesn't get a chance to enjoy them anymore because of his travel and other time commitments.

John also put his vast record collection on the market last year through Christie's.