I know a few, but I'm only really a 'master' at PHP, (x)HTML and CSS.

I'm currently giving C++ a go, I've done some work with the Win32 api although that stopped when I switched to Linux as my OS of choicce. I know some of the OpenGL API (I can draw 2D triangles and squares). I'm not too bad a Javascript but don't ask me to do anything too advanced in it or I'll fall to pieces.

I'm thinking about Learning Java, anybody got any advice on that? :)