There are a range of services out there already. There was a YCombinator startup where you could sign up and be a volunteer "listener" after completing some onl

There are a range of services out there already. There was a YCombinator startup where you could sign up and be a volunteer "listener" after completing some online training - sorry forget the name now - it was designed to solve the issue you are talking about. There's also Interpals - a free penpal service. You can use it to learn languages too, although some people seem to use it as a dating site!