Earthwatch has a whole host of arranged trips or expeditions which give paying volunteers the opportunity to get involved in different aspects of scientific research or other similar activities. Be warned, these are not cheap! They do, however, incorporate some rather unique projects and appear to put volunteers in direct contact with professionals working in this field. Earthwatch also operates in a wide variety of countries.

Expeditions range from a week in a mammoth graveyard in the western US ($2500) to maternal and child healthcare in Chennai, India for two weeks ($2300) or helping protect Armenia’s cultural heritage by helping document it ($3100 for 11 days).

Transportation to the site is not covered, but meals and accommodation, as well as an apparently substantial supervision or training component, are.

There are extensive personal accounts available in the blogs section, and categories of trips include teen, family and group expeditions. And now I know why teachers are always so enthusiastic about such trips: if you lead a group of six or more paying participants, you may be able to go along for a discount or for free!