Instructables!

Um écran magnético:

http://www.instructables.com/id/Wooly-Willy-Table/

Um Skate/Segway:

newbox.TV

http://www.instructables.com/id/Easy-build-self-balancing-skateboardrobotsegway-/

...E um Micro-Cofre, dum Baralho de cartas:

>http://www.instructables.com/id/Card-set-to-hide-things-in/