A couple of months ago I enrolled myself in an online Estonian class.
At the time, I figured that, you know, I should probably start learning some Estonian before I leave late this summer. And the course is taught through Tartu University, so I thought it would be perfect--I could actually go to the University for the final test while I'm in Tartu!
I also have a book that I've been learning from, and it has helped me so much. I've already got three out of fourteen grammatical cases down. I'm so proud.
(By the way, I am so very happy that Estonian doesn't have noun genders...)
Now, before I had enrolled myself in that course, I had done some internet scouring and was able to find a multitude of awesome links for language learners. Here are some of my favorites....
http://mylanguages.org/index.php - Great website with almost any language you could want. Pretty comprehensive.
http://www.livemocha.com - Chances are, you've heard of this. It's a good site with a bunch of languages. I haven't done much more than the first few lessons of Estonian, but it's given me a good vocabulary upon which to build later.
http://www.oneness.vu.lt/languageschool - This may be for Estonian learning only, but it's still got some good lessons and exercises. You should probably learn Estonian now. (DO IT.)
http://www.loecsen.com/travel/discover.php?lang=en - The basics for a few languages.
http://www.fluentin3months.com/ - An interesting blog with some good/funny articles for all you polyglots to read.
For Anything Else:
http://www.cultures-shocked.org - Anyone who is an exchange student, will be an exchange student, will be hosting an exchange student, or knows an exchange student should learn some things from this forum!
http://www.everyculture.com/ - Learn about the world's cultures, man.
Äitah ja head aega!