I am a member of DANTE e.V. - the German language TeX users group. Actually I am not only a member, but also on the board. I am also a tex.stackexchange representative at TUG.
During my spare time I am running a small company that uses LuaTeX in its main product (www.speedata.de, http://speedata.github.com/publisher/ - the source code).
And when I am bored, I update my german LuaTeX blog.