Here is a big organization that arranges volunteer opportunities aboard -they have programs in
They also have various areas of focus for your placements- from health to economic empowerment to women. Their placements can last from 1 week to 12 weeks.
"Cross-Cultural Solutions is a non-profit 501(c)(3) organization founded in 1995. Today, 25,000 people have participated in our volunteer programs in Africa,Asia, Latin America, and Eastern Europe. CCS has a worldwide staff of over 300 people in 12 countries, with administrative offices also located in the United States, United Kingdom, Canada, and Australia. In the UK, CCS is a Registered Charity (No. 1106741) and a Registered Company Limited by Guarantee (No. 4991010). In Canada, CCS is a registered non-profit corporation (Federal Corporation No. 445810-9). Steven Rosenthal founded CCS in 1995 and serves as its Executive Director.
CCS has been profiled in more than 500 news outlets, including: CNN, The New York Times, The San Francisco Chronicle, Time, Newsweek, The Chicago Tribune,The Toronto Star, The Today Show, USA Today, National Geographic Traveler, and the ABC Nightly News."