Rubiks Cube
Well my birthday is coming up soon and the only thing I want is a Rubiks Cube 4×4.
I have many 3×3 cubes which I can solve (quite) fast, and I have taught many people over the years.
I actually have to admit that I never really figured out how to solve them myself, my Grandad actually showed me many many years ago.
It looks like there are a lot of online stores in Germany which sell them http://www.google.de/products?q=Rubik+Cube&btnG=Produkt-Suche