Linked cranks mechanical puzzle

Here is my current favourite MOC:

<http://www.youtube.com/watch?v=O7_wfKJAX7s>
<http://www.brickshelf.com/cgi-bin/gallery.cgi?f=418894>

It's a Lego implementation of an amazing mechanical puzzle invented by 
Oskar van Deventer and Bram Cohen, as seen here:

<http://www.youtube.com/watch?v=j6J_cHM9mEw>

I can't improve on the explanation given in this second video - just watch it!
Basically it's a puzzle a bit like Rubik's cube, in which you scramble it and
then try to get back to the starting position.  (Much easier than Rubik's cube,
but a very interesting mechanism).

Planetary gears like in the original did not seem practical, so it was quite an
interesting challenge fitting the necessary gearing into this small space.  (My
first attempt fell apart because there was actually no connection between the
two halves!)

I think there's great potential for mechanical puzzles in Lego - I've seen a few
but not many...

Enjoy!  Alexander