Celebrities have always aligned themselves with good causes. Any list would have to include Audrey Hepburn, who worked with the United Nations International Children's Emergency Fund from 1988 until her death in 1993 and Humphrey Bogart, who led a 1947 group that protested the U.S. government's probe of communism in Hollywood. However, the last few years have seen a considerable increase in the depth of celebrity's involvement.

Whether it's Bono flying to Africa with America's Treasury secretary or Lindsay Lohan's sabbatical to Kenya to work with AIDS sufferers, more stars than ever are pushing their political and social views into the public domain in an effort to change the world.

Whether this is a welcome development depends on your perspective. There can be little doubt that the organisations that have the star's endorsements are ecstatic for the extra publicity which they are getting.

So, you may ask, why would anyone object to these efforts? Well, for one, there is a sense that celebrities don't really understand the problems about which they speak and, as the title of this piece suggests, they are solely doing it to boost careers which are in various stages of dilapidation, ruin or in need of an extra boost of publicity.

Recently, the media darling that is 'Brangelina' - Brad Pitt and Angelina Jolie, of course - have seemingly spent more time in Africa than they have 'back home'.

Amongst other causes, Jolie has found herself involved in a 'Diary' show broadcast on MTV (available to watch at http://www.mtv.com/overdrive/index.jhtml\) showing her "getting down and dirty" in Africa and, amongst other things, stating the importance of putting money into village-level programs so as to alleviate poverty. This is all well and good but, yet again, this is not her field of expertise and it should come as no surprise that Miss Jolie was opening a movie around the same time as her humanitarian adventure.

Brad Pitt 'led' a similar expedition to Ethiopia and, in a similar vain to Jolie's voice of concern, it came across as shameless self-promotion disguised as compassion. It should come as no surprise that Mr Pitt also had a movie coming out at the time of the show's airing.

Another actor who has also recently arrived back from a trip to Africa promoting his own passion for fighting AIDS is Matt Damon. Maybe I am being somewhat cynical when I question Damon's motives for the trip, but I feel the fact that he has slipped under the 'Hollywood radar' as of late, and has one film on its way to the box office and a massive five in post-production (including Ocean's Thirteen and The Bourne Ultimatum) may have had something to do with it.

Even the not-so-old-and-jaded of Hollywood have begun to get involved in the 'Big Issue' that is Africa, at a time when one can say that not since the 'hippy' decade of the 1960s have so many entertainers believed that they can rescue the world.

A fine example of this comes in the form of young, multi-talented starlet Lindsay Lohan. Lohan (19) has recently taken time out from her blossoming acting and singing duties to help the poverty-stricken people of Kenya with charity organisation One Campaign. Meighan Stone, a spokeswoman for the organisation, was quoted as saying "As with Brad Pitt and other celeb visits, it'll likely focus on where America is helping make a difference to save and change lives." It seems, from this statement, that the trip is not even intended to make a difference in Kenya, but rather focus on providing good press for America. When you think about it, how many people in Kenya do you think actually know who Lindsay Lohan is? Yet again, it should come as no surprise that Miss Lohan has a new movie to plug and the media will obviously be all over the 'goodwill mission' like a rash.

However, the main celebrity double act we most associate with African causes is Bob Geldof and Bono (of U2 fame).

Geldof has, for more than twenty years now, been pushing the same moral message upon the masses - "this can't go on". His views are often presented as fact and, in most people's minds, he is now widely considered as THE spokesperson for Africa.

During last years G8 summit both he and Bono delivered ringing endorsements of what had been achieved. Geldof claimed that the people of Africa had "got more from the last three days than they have ever got at any previous summit.", and Bono went so far as to add figures into the equation claiming, to great fanfare of course, that "$25 billion of new money" was being pumped into Africa by 2010. What he failed to mention was that most of this wasn't actually "new money", but, rather, came from either previous pledges or future aid budgets. Bono, with considerable emotion in his voice, had put on an acting performance Bogart or Hepburn themselves would've been proud of.

Once more, one has to question whether Bono's U2 would be Britain's second richest band (toppled only by Chris Martin's Coldplay who, incidentally, is another celebrity big on African issues. Are we beginning to see a pattern emerge here?) if it were not for Bono's humanitarian work.

Geldof is rumoured to be worth an estimated $73 million, and the release of certain of his 'artistic' projects seem to be more than a little coincidentally linked to his involvement with Africa. A month before Tony Blair's report on Africa was publicly unveiled by Geldof and Blair, Universal Music released a greatest hits album of Geldof's former band - the Boomtown Rats - and digitally re-mastered versions of their six studio offerings. This was quickly joined by a six-part BB1 series, entitled 'Geldof in Africa', and the re-release of Geldof's 1986 autobiography. More than a little suspect, don't you think?

Geldof's somewhat questionable motives haven't gone unnoticed by the African people either. Marches have been held against Geldof's 'neo-colonial' attitudes towards Uganda in the capital, Kampala, and Sudanese hip-hop artist stated he thought Geldof was trying to "make history by using the poor people." and that many other Africans had lost all respect for Geldof.

The use of celebrities to promote political campaigns is in danger of promoting the idea that it is us, the Westernised world, with the power and money and all the Africans are doing is looking for a free hand-out. This can only be damaging in the long run and seems to be perpetuating a colonial notion of power and powerlessness. Also, as I have already mentioned, the simplification of the causes by celebrity's involvement may well be taking away from the overall severity of the issues at hand.

However, one must look at the positive impact celebrities are having on Africa. Yes, many may be benefitting from their involvement, but thanks to them more people now have at least some awareness of the issues regarding AIDS and poverty in Africa, and even the little money that is trickling into the continent is better than nothing. I can't say i've done anything better to help the people of Africa, and until I can, I'll try not to criticise those that try.