Just passing on a pretty cool link (and possibly the best use of social networking software anyone’s yet thought of): LiveMocha, a website where you can take language lessons for free. Currently, you can enroll in Spanish, French, German, Hindi or Mandarin Chinese lessons. The neat thing about the site is that you can connect with native speakers and interact with them either bulletin-board style, or via audio recordings (if you have Skype or some other kind of recording method). That way you can get expert feedback on how well you’re learning to write or speak. And you can also help people who are trying to learn English. The online lesson programs do have some technical quirks and I suspect a serious student would still want to supplement them with traditional books or tapes, but it’s not bad for free lessons.
Although I wish they’d offer more languages (so I could reconnect with my limited Russian that I learned in college), I’m currently taking Hindi lessons — I occasionally watch Bollywood movies, and would like to know how to communicate something other than my undying love for someone. (Did you know that the Hindi word for “snow” is barf? No lie!)