My primary research interest involves language. My current research is in statistical machine translation, which basically means I spend my time designing statistical models for translation and training them on example documents translated by humans (“training” just means that I find the parameters of the model that “explain” the data). If you are interested in computational linguistics, you should have a look at the course notes from a class that my advisor taught in Fall 2003.
I'm fluent in English and Iraqi Arabic. I speak a bit of French and know a few phrases in Mandarin (enough to get myself into trouble, anyway).
I'm told that the best way to learn a language is to go to an area where that language is spoken (as exclusively as possible) and to immerse yourself in the language. I'm hoping to try that out soon! If you're stuck where you are as I have been, I'm told that videos and CDs can be very helpful.
In particular, the French in Action series is supposed to be quite good (I have been told that this series justifies having a television) and it can be watched free online here. The videos are just one part of a course, which also involves writing and reading exercises, but I'm told that one can acquire a working knowledge of Parisian French by abusing the system and simply watching the entire series (51 videos, ~25 minutes each) a few times.
Unfortunately, I haven't found equal resources for other languages. If they exist, please let me know! In the mean time, Thackston is a good introduction to Quranic Arabic, and Zhongwen is the most useful Mandarin resource I've found online.
Typing in other character sets (such as Arabic) under X can be difficult. For nice documents (in LaTeX, of course), I recommend ArabTeX. For just routine typing, I've written a keymap which is not the same as the normal one for Arabic keyboards. It is written to be more intuitive for people that use English keyboards (the L key is mapped to lam, the N key is mapped to nun, etc). I find it much easier to touch-type in Arabic with this map. YMMV. To use it, type:
$ xkbcomp arabic.xkb :0and then hit [F12] to switch back and forth between Arabic and English. GTK2 does a very nice job of rendering Arabic. Here's a screenshot from gaim.