By BBC News Online's Ryan Dilley

When asked, most people will describe paradise as a sun-kissed desert island, replete with shady palm trees and a hammock swinging in the fragrant tropical breeze.

The release of Leonardo DiCaprio's latest film The Beach, set in just such an earthly paradise, is bound to tempt hordes of pasty malcontents to head for the South Seas.

But before you pack your flip flops and fishing spear, can you be so sure there are any unspoilt beaches left in the world?

Phi Phi Island in Thailand was the location for DiCaprio's film. Locals and environmental groups alleged the area was damaged during the shoot and called for compensation.

Both DiCaprio and Twentieth Century Fox deny the claims, yet the furore highlights the inherent fragility of unspoilt holiday destinations.

Jennifer Cox, from The Lonely Planet guides, says Thailand bristles with tiny islands.

Tourist trap

"Many have been developed for tourists - some badly. There are an increasing number of people going travelling, and the impact they have on the places they visit is a real problem."

As the reputation of even remote beaches spreads and the number of visitors swell, local people begin to provide the goods and services they think western visitors will want.

"Suddenly you have a tourist enclave," says Ms Cox. Despite all the problems of rubbish, cultural clashes and unplanned development, tourism can aid the people in these usually impoverished regions.

Ms Cox points to the Full Monty effect, where the 1997 film was forecast to bring tourist money to the UK's depressed steel heartland.

"Why is that a good thing for Sheffield, but not a good thing for Thailand? Provided there's an infrastructure (transport, sewage, planning) so tourism can be sustainable and benefit local people," Ms Cox says.

"Backpackers go to places everyone knows about and complain about development - but there are plenty of other places left to discover."

BBC survival expert Ray Mears agrees: "Unspoilt places do still exist. In fact there are quite a lot of them."

This may be good news for those of us who crave not a holiday, but a new life.

Desert island deserters

While few may envy those hardy souls dispatched to the windswept Hebrides for the BBC's Castaway 2000 show; who would pass up the desert island retreat offered on Channel 4's Shipwrecked?

However, the 16 under 25s who volunteered to spend 10 weeks living off the fat of the land on the tropical island of Monturakau, found the experience less than idyllic.

With tempers as short as their food supplies, half of the group departed before the experiment had run its full course.

Ray Mears, who has himself just returned for a stay on a desert island, reckons that with a little ingenuity their stay could have been far more salubrious.

"They're a fantastic environment. If you're lucky and have a good island you'll have tropical almonds and cashew nuts to eat."

Mr Mears admits some islands lack sources of fresh water, but coconuts can offer a decent alternative.

Go nuts

"You can drink the liquid of up to four immature, green coconuts a day - that's four litres - more than that and it has a laxative effect."

With the aid of a good cutting tool, the coconut palm can give the castaway virtually all they need.

"The coconut is considered by many South Seas peoples to be the 'Tree of Life' for many good reasons."

Almost every inedible part of the tree can be used. Sun visors, shelters and animal traps can all be fashioned for it.

"Mosquitoes can be a problem on some islands, but an improvised mosquito net can be made from coconut fibre," explains Mears.

Should you tire of coconut for breakfast, lunch and dinner, you have only to look to the larder all around you - the sea.

Sea food

"A lot of the food you need will have to come from the sea. If you can't swim, then you're in trouble," says Mears.

While splashing around with your homemade spear, Mears recommends you keep an eye open for the deadly dangers of the deep.

Luckless fishers may come a cropper, should they encounter sea snakes, scorpion fish, cone shells, lion fish or the notorious blue ring octopus.

In which case, they might find themselves tasting a rather more Biblical version of paradise than they intended.