A personal favourite of mine from his collection is his 'Natural Top' boxes. Take a look at this video example:
Now watch the man himself in action, it's not hard to get your head around the principle but the precision is amazing, and how the hell does he remember how each piece goes back together ?!
The perfect gift for any gender and any age so head along to Ray & Kathy's web site Temima Crafts for more information :-)