As we speak, I'm diving in to the internet to try and discover more about Charles and Ray Eames' House of Cards (thanks to Tina for the heads up).
An interlocking system of cards with either images (I think the smaller cards) or single colour panels (the larger versions),the six slots of each card let you slot together the two dimensional images into three dimensional shapes.
I love the idea of putting together ideas in a three dimensional structure like this. I'm going to get a set from somewhere, have a play and report back.
Of course, I'd love to have a play with the Computer House of Cards, done for IBM's Pavilion at the World's Fair in Japan in 1970, but at $650 for one of the original packs, I'm not sure I'll have a chance any time soon...