Alternatives to the Peace Corps. order it from http://www.foodfirst.org/node/1338/print. it's only $12.
the Mexico Solidarity Network  runs great programs, short and long term: they have internships, study abroad, and also an activist training program in México.
 is a US organization that puts recent college graduates into public schools for 2 years to bring your energy to the young people who need it the most. you are paid for this work but you do not need a teaching credential. you also receive nearly $10,000 at the end of your service, with which you can repay student loans.