By BBC News Online's Orla Ryan

Bob Geldof first made his fame and fortune by not liking Mondays.

Now he is as well known for the businesses he runs as for being one of Ireland's first big musical exports.

This week, he struck a deal which will see his media and event company 10 Alps Broadcasting list on the London Stock Exchange on 30 July.

Geldof is now almost as famous for the businesses he runs as the songs he wrote

Mr Geldof is one of several celebrities who have channelled their creativity into business ventures - but not all of them have shared his success.

The deal will see 10 Alps Broadcasting - formed with Alex Connock with what was left from the sale of Planet 24 in 1999 - take over the publicly quoted marketing and communications business Osprey Communications.

The new firm will be worth about �9m and Mr Geldof will own about 12% of the shares.

According to the 10 Alps website, his other business interests range from smart cards, online travel as well as a stake in the company which owns the Survivor TV format.

He has not just assumed that because he is Bill Wyman, he will do well Sticky Fingers spokeswoman

But how involved is he in the running of 10 Alps Broadcasting?

"He is very involved at a practical level. He will ring me between five and ten times a day," Alex Connock, chief executive of the new company, said.

"You won't find Bob at eight in the morning at a management or accounting meeting, but there is no reason for him to do that. If you were to sit him down and ask him the strategy, he would absolutely be able to tell you."

Connock sees no downside to celebrity involvement in a business. But he stresses that people should "form an opinion based on dealings with us not on their view of Bob Geldof".

Celebrity dot.gones

But sometimes, all the celebrity help in the world cannot help a company in a falling market.

Many celebrities lent their name, money and expertise to internet ventures, which have failed to stay the pace.

Joanna Lumley may now turn her back on internet investments

Joanna Lumley was involved in Clickmango.com, the health and beauty website, which failed to secure a second round of funding.

Jonathan Ross and Matthew Freud saw their investments disappear, when dot.com retailer Toyzone closed its virtual doors.

Some other celebrity entrepreneurs have yet to see how their net investments will pan out.

You won't find Bob at eight in the morning at a management or accounting meeting, but there is no reason for him to do that Alex Connock

David Bowie lent his name to USABancshares.com, an internet bank where you could get Bowie-branded cheque books and credit cards.

Manchester United's Sir Alex Ferguson is a shareholder in toptable.co.uk, a restaurant information and booking service.

Toptable's managing director Karen Hanton stresses that he is not a token investor, on board only to garner publicity.

"He is kept fully informed of how his investment is doing, he obviously passes through to us any ideas he has about areas we should be looking at."

Planet Hollywood

A more traditional route for celebrity entrepreneurs is the restaurant business.

Planet Hollywood - backed by Demi Moore and Bruce Willis - spawned a host of imitators.

But the restaurant group ended up filing for bankruptcy protection in the US.

It was hit hard by its aggressive expansion but did eventually find new investors in Prince Alwaleed Bin Talal, of Saudi Arabia, and Singaporean property magnate Ong Beng Seng.

Others, such as the Fashion Cafe, weren't as lucky.

"Models and food don't really go together," a spokeswoman for Sticky Fingers pointed out.

Sticky Fingers - now a part of the Maxwell restaurant group - was set up by Rolling Stone Bill Wyman in 1989, taking his inspiration from the album of 1971.

"He has not assumed that because he is Bill Wyman, he will do well," the Sticky Fingers spokeswoman said.

"You have to have marketing, operations and service working right. You could be Tom Cruise and nobody will come to your place."

When the celebrity has the right attitude, there is room for cross-over promotions.

She added that if Wyman was working on music or other creative projects, the restaurant was in regular touch to see what tie-ins could be done.