probably you've heard of the "introduction to artificial intelligence" online course given by professors Thrun and Norvig from Stanford. What's really fascinating about this topic (at least for me as a programmer) are the unusual patterns and principles used. Here's a simple demo: 

http://kultur-und-stress.de/Demo/LanguageMatcher/applet/index.html

Type or paste some text. Use one of 5 languages: English, German, Spanish, French, Italian. While you type, the program will try to guess which language you are using. As the text gets longer, the match should get more accurate. 

This sketch and the associated library are amazingly simple, and got the "feel" of these 5 languages by digesting the first few sentences of Kafkas "The Metamorphosis", in the original German and translated in the other 4 languages.

... " One morning, when Gregor Samsa woke from troubled dreams"...