During my studies, I learned a few programming languages such as: C, C++, Visual Basic, VBA, MATLAB, Haskell, Prolog, HTML, XML, PHP and also, ASP.NET.
There are also other languages that I learned about but I am yet to master, like: EIFFEL, Squeak "SmallTalk", Mathematica.
Currently, I am studying Javascript which seems really interesting. Take a look at the following examples:
Google Logo!
Minimum Spanning Tree
Forbidden Graph