Today, I discovered My Language Exchange. This (commercial) website connects people that want to help each other learn a language. Quite a lot of people signed up on the site, so that you can even find people to help you learn Yiddish or Thai.

However, I guess that not everyone included in the database is as highly motivated as this one:

German is the single greatest language on the face of the earth, and every moment that goes by in which I am not entirely fluent in it, is a moment I would rather not have lived.