For many, independent travel is a daunting task, and the prospect of joining a group with a pre-determined objective is attractive. Others may feel that they wish to make a contribution to the communities or environment through which they travel. The options open to such individuals are enormous: from adventure holidays to community work and scientific fieldwork overseas. The better-known and well- established groups can be found in specialist directories or on the internet. It may be more difficult to find out about the credentials of smaller and/or newly emerging groups. Almost all will require some sort of financial contribution. Don't be afraid to ask questions, either about the organisation itself or what your payment covers. Try and get a feel for the organisation, and if you are not happy with its overall aims or the attitudes of the people who run it, don't sign up. Whether you want to climb Everest, walk to the South Pole or visit a remote tropical island, there is now a tour company out there to help you achieve your dream. Naturally, you pay for someone else to organise your expedition, but the preparation time and responsibilities for you are correspondingly less. For example, the WEXAS members' Discoverers brochure has many such trips; others are advertised in outdoor-interest magazines and the national press. The useful directory Adventure Holidays (Vacation Work Publications, 9 Park End Street, Oxford OX1 1HJ, tel 01865241978, website www.vacationwork.co.uk) lists holidays by the type of sport or activity. Magazines such as Traveller, Wanderlust, Global Adventure and Geographical, and the travel sections of the weekend newspapers, are useful for finding out more about the unusual and exotic.

There is an increasing trend to combine an adventurous journey with the challenge of raising funds for a charitable cause. The initial financial contribution required to join these charity fund-raising expeditions is often low, but the effort required to meet both challenges can be immense. Be prepared to train hard. Whatever the organisers tell you, you need to be fit and acclimatised to the conditions you are going to meet. And when it is all over and your friends' hard- earned cash is on the way to the charity, satisfy yourself that it is being well spent on a cause dear to your heart.

Adventure holidays and genuine expeditions differ in many ways. A scientific expedition will be expected to add to human knowledge, to 'discover' something new. Those joining such expeditions will usually be expected to give up considerable time to help with preparations, be whole-heartedly committed to the project's overall aim and objectives, and be capable of working as a skilled member of the team. And that is to say nothing of the efforts required to raise the necessary funds for the expedition.

In Britain, the Royal Geographical Society (with The Institute of British Geographers) at 1 Kensington Gore, London SW7 2AR (website www.rgs.org) is the principal organisation concerned with helping those carrying out scientific expeditions overseas. Through the work of its Expedition Advisory Centre (tel 020 7591 3030), the RGS-IBG provides information, advice and training to 500 or so groups each year - groups that carry out scientific and adventure- and youth-oriented projects abroad. For those who have a clear idea of what they want to do and have already formed a group of like- minded individuals, the centre has a number of useful services, including the annual seminar on planning a small expedition that takes place each November.

Many of the groups helped by the centre are based at schools and universities, as the principle of outdoor adventure and challenge is widely accepted as an important training ground both for young people and potential managers alike. As a result, a number of charitable and commercial organisations now offer expeditions to people of all ages. The Expedition Advisory Centre publishes a directory of these, entitled Joining an Expedition. The directory includes advice on choosing an appropriate project and ideas for raising funds to join projects. Many of the organisations listed in the directory can also be accessed via the Expedition Advisory Centre's website (www.rgs.org/eac). Individuals with special skills to offer - doctors, nurses, mechanics and scientists - are invited to become listed in the register of personnel available for expeditions that is maintained by the centre and used by expedition organisers to recruit skilled volunteers and staff.

Amongst the well-established youth-focused exploration societies, there are: · Brathay Exploration Group (Brathay Hall, Ambleside, Cumbria LA22 0HP, tel 015394 33942, websitefreespace.virgin.net/brathay.exploration) and The Dorset Expeditionary Society, (Budmouth Technology College, Chickerell Road, Weymouth, Dorset DT4 9SY, tel 01305 775599, website www.wdi.co.uk/des). Both send out several expeditions each year, both within the UK and abroad, and members tend to be between the ages of 16 and 21.

· The British Schools' Exploring Society, (1 Kensington Gore, London SW7 2AR, tel 020 7591 3141, website www.bses.org.uk) organises six-week-long expeditions for 17- to 20-year-olds during the summer holidays and six-month-long expeditions for those in their 'gap' year between school and university. BSES Expeditions has always had a strong scientific component to its work and provides an excellent training for those hoping to go on and organise their own research expeditions.

· Raleigh International (27 Parsons Green Lane, London SW6 4HZ, tel 020 7371 8585, website www.raleigh.org.uk) regularly recruits 17- to 25- year-olds to take part in demanding community projects and conservation programmes that last up to 12 weeks. With increasing public concern for the environment, a number of other organisations offer a chance to get involved in conservation projects overseas on a fee-paying basis. Among them are:

For many, the experience of meeting and working alongside people in the host country is one of the great attractions of travel:

Those wishing to work or study abroad without necessarily joining an expedition should consult the Central Bureau (10 Spring Gardens, London SW1A 2BN, tel 0207389 4004, website www.britcoun.org/cbeve), whose publications are extremely useful. The Bureau, which also has offices in Edinburgh and Belfast, holds details of jobs, study opportunities, youth organisations and holidays in some 60 countries. Vacation Work Publications (9 Park End Street, Oxford OX1 1HJ, tel 01865 241978, website www.vactionwork.co.uk) publishes many guides and directories for those seeking permanent jobs or summer jobs abroad, unusual travel opportunities, voluntary work and working travel.

Often travel for its own sake seems insufficient for those who wish to provide practical help for locals in the country they are to visit. If you feel that you have both the time and the specialist skills needed to be a volunteer with one of the aid and development agencies, you should probably start by reading two very helpful directories: Volunteer Work (Central Bureau) and/or The International Directory of Voluntary Work (Vacation Work). Both books give an outline of the organisations which are willing and able to accept volunteer workers on overseas projects, as well as information about the skills and level of commitment required of the volunteer. At this stage you should be aware that the majority of host countries that welcome volunteers usually require skilled personnel such as nurses, teachers, agronomists and civil engineers. They may be unable to pay even your airfares (although many provide board and lodging) and you may be expected to help for at least one or two years. Remember that during that time you probably won't be travelling but will be based in a poor urban community or remote rural village.

If you feel that you are suitably qualified and have the emotional maturity to be a volunteer, you may like to discuss your hopes and ambitions to serve with someone who has already been on such an expedition.

If you wish to work for an international aid organisation, the World Service Enquiry (Bon Marché Centre, Suite 233, 241- 251 Ferndale Road, London SW9 8BJ, website www.wse.org.uk) has been advising people wanting to work overseas in the developing world for more than 25 years. Its annual guide outlines a range of options and organisations and its monthly magazine, Opportunities Abroad, lists the latest aid, development and mission agencies' vacancies. Volunteer Work Information Service (Case Postale 90, 1268 Begnins Vaud, Switzerland, website: www.workingabroad.com) provides the Complete Resource Guides to Voluntary Work, a specialist publication listing voluntary work opportunities by continent and personalised service, which provides individual country information to enable volunteers to work or travel overseas.

Finding the right organisation to suit you can take time, so don't expect to leave next week. Four major agencies which send out volunteers from the UK as part of the British Government's overseas aid programme are International Cooperation for Development (ICD) (Unit 3, Canonbury Yard, 190A New North Road, London N1 7BJ), UNAIS (Suite 3A, Hunter House, Goodramgate, York YO1 2LS), Skillshare Africa (126 New Walk, Leicester LE1 7JA) and Voluntary Service Overseas (VSO) (317 Putney Bridge Road, London SW15 2PN). Over 400 volunteers go abroad each year through these organisations; all of them are over 21 years old and have relevant professional work experience.

Those with medical skills to offer might like to contact Health Projects Abroad (PO Box 24, Bakewell, Derbyshire DE45 1ZW, tel 01629 440051, website www.hpauk.org), which publishes a useful booklet, the HPAGuide to Voluntary Nursing Overseas, and recruits unskilled volunteers for health-related projects in Tanzania. The International Health Exchange (8-10 Dryden Street, London WC2E 9NA, tel 020 7836 5833, www.ihe.org.uk) publishes job vacancies, runs training courses and maintains a register of healthcare professionals wanting to work in developing countries. Merlin (Medical Emergency Relief International) (5-13 Trinity Street, London SE1 1DB, tel 020 7378 4888, www.merlin.org.uk) is a well-respected agency sending qualified medical and support staff to emergency zones worldwide.

So, whatever motivates you to go on your expedition of a lifetime, you can be sure there is someone out there to help you realise your dream. There is nothing like travelling with a purpose to help you to understand the world and all its complexities better.