Here's a list of companies offering educational and volunteer opportunities in South America.
AmeriSpan (tel. 800/879-6640 or 215/751-1100; www.amerispan.com) helps students arrange programs that combine language study, travel, and volunteer opportunities, throughout South America.
Amigos de las Américas (tel. 800/231-7796 or 713/782-5290; www.amigoslink.org) is always looking for volunteers to promote public health, education, and community development in rural areas of Latin America.
Earthwatch Institute (tel. 800/776-0188 or 978/461-0081; www.earthwatch.org) supports sustainable conservation efforts of the earth's natural resources. The organization can always use volunteers for its research teams in South America.
Habitat for Humanity International (tel. 229/924-6935, or check the website for local affiliates; www.habitat.org) needs volunteers to help build affordable housing in more than 79 countries in the world, including most countries in South America.
Spanish Abroad, Inc. (tel. 888/722-7623 or 602/778-6791; www.spanishabroad.com) organizes intensive language-study programs throughout Latin America.