For over 60 years, The Student Letter Exchange has matched English speaking Pen Pals with students, ages 9-18, across the US and around the world. http://www.pen-pal.com/
Find Military Pen Pals and Forces Friends. Forces Penpals is designed to help you get in touch with new friends online for pen pals, friendship and dating. http://www.forcespenpals.com/
A confidential, nonprofit pen pal service geared for the disabled & anyone else interested. Quarterly newsletter published. Membership fee charged http://www.freewebs.com/cghcfriends/
The national military morale mail pen pal campaign that gives recognition to those who go above and beyond the call of duty in their support of our men and women in uniform. http://www.militarymail.org/
Since 1989, SAPE (formerly 'The Soviet-American Penfriend Exchange') has matched more than 30,000 people from all over the world with penpals in the former USSR and Baltic countries. http://www.geocities.com/Heartland/Ranch/6689/
Free penpal list for people who wish to practice Spanish with Spanish speakers and who are learning English for mutual benefit. http://lingolex.com/cc/intercambio.htm
Will enable you to learn languages and make friends at the same time. Find people who share your interest in a language http://www.languagepenpals.com/