Whoopi Goldberg, Cindy Crawford, Jonathan Ross and the Antiques Roadshow's Hugh Scully have all done it. Geri Halliwell is mulling it over. David Beckham, Michael Owen and Alan Shearer are about to sign up.
The eclectic mix of film stars, models, television presenters and footballers are, or are about to, act as the public faces of fledgling internet companies.
At a time when the internet is transforming business practices, the value of some things, such as the cachet of celebrity, remains resolutely the same. Following the stellar performance of many internet shares the stars are increasingly looking for a piece of the action.
New start-ups looking to build brands and credibility as quick as possible are fighting to sign up celebrities to publicise their services. Unlike with traditional endorsement contracts the deals are not straight cash arrangements. The stars, having seen the massive gains made by the shares in the more successful dot.coms are demanding equity and, in some cases, an input on business strategy. For start-ups starved of cash equity is a great way of paying the bills.
Inevitably in a land where both dot.coms and celebrity are valued more highly than anywhere else, the US has led the trend. Ms Goldberg has a two-year contract to act as a creative-marketing adviser and spokeswoman for flooz.com, an online gift currency provider. She says she likes the ownership aspect of her contract. "If I'm going to bust my butt out there, I want a piece of it," she told reporters.
Ms Crawford joined the board of eStyle, a Los-Angeles based online womens retailer, when it wanted to launch a babies site aimed at mothers and mothers to be. She was pregnant at the time and now hosts on-line chats recommending products for consumers with young children based on her personal experience with her new baby.
William Shatner, who played Captain Kirk in Star Trek, is said to be sitting on a paper fortune of millions after agreeing to become celebrity spokesman for priceline.com in 1998. Drag queen Ru Paul has stock options in WebEx, a California based interactive web meeting service.
Publicist Matthew Freud, who is the founder of on-line toy shop Toyzone.com and employs Jonathan Ross as the company's public face, says a carefully chosen celebrity can give an internet brand instant recognition. "It is a very quick way of establishing a brand. We chose our celebrity very carefully. Jonathan is like what Toyzone set out to be. Enthusiastic, irreverent, a bit child like but in an adult way.
"Jonathan has a standard endorsement deal but rather than there being a dollar sign at the end of his contract there is an equity figure. He is a participant in the business rather than just a hired hand.
"He's a passionate toy collector with a virtually definitive comic library and one of the biggest collections of Japanese robots in the world. He advises us on what sort of toys people want and has strong opinions on what the next craze will be."
On-line auctioneer QXL.com has paid Mr Scully around £3m to give up his position on the BBC's Antique's Roadshow and value customer's goods by email. QXL hopes Mr Scully will attract "silver surfers" to the site.
Mr Freud admits that star endorsements are no guarantee to business success. "Planet Hollywood went from zero to hero instantly because of celebrity equity but there was no sustainability behind the concept," he said.
The stars themselves are aware that only a few internet start-ups are likely to survive in the long-run and that they have to be selective about which one they pin their colours to. At the moment Mr Ross appears to have picked a winner. He has 1% of the equity in Toyzone, which advisers Lehman Brothers may float later in the year for up to £250m.
However, Ms Halliwell, the former Spice Girl, turned down the chance to front one of the recently launched women's portals because she did not think it was the best vehicle for her talents. She is considering other offers.
Footballers David Beckham, Michael Owen and Alan Shearer have been inundated by endorsement offers from sports driven start-ups. Their agency, the UK sports division of US entertainment group Sfx Entertainment, says that after sifting through dozens of offers the trio are on the verge of signing deals that should net them several million dollars over the next two to three years.
"Picking the company to go with is like trying to pick which horse to back in the Grand National," said managing director Jon Holmes. "Except in this case there are 250 runners with no form and no-one is quite sure whether this is a race over hurdles or the flat."
Mr Holmes says that to protect the interests of his clients he has negotiated deals that combine equity and cash. Either way his partners win.
