Codecademy - learning cloud, on the cloud

I recently bumped into codecademy - a perfect example of how advancing technology is a self-replicating process.

The home page, containing a short introductory lesson

The site allows you to take short 'courses' in javascript, in which you can complete exercises either through a virtual console or by typing out the code and running it. The site responds with tips and additional tasks as you progress.

So far there are just two courses available - one basic introduction to javascript, and one as a sort of conversion class for developers new to JS but well versed in another language.

I would like to see courses in other languages available, but this is a fantastic site nevertheless. Kudos to the creators - Ryan Bubinski and Zach Sims.