For all you with Lego kids at home or those closeted adult fans of Lego, here is something fun -- nanoblocks. They are micro-sized Lego-esque bricks designed by Kawada of Japan and distributed by The Ohio Art Company, maker of the Etch-A-Sketch. The smallest pieces measure a mere 4x4x5 mm! While I'm not a fan of some of the other brands of Lego-type building bricks, I think the nanoblocks are really well made and pretty cool. The instructions are mostly wordless diagrams like Lego, but at least with this castle, you build from the bottom up, layer by layer, instead of building sections and joining them together. So, the instructions can be a little tricky for younger kids.
Here is the Neuschwanstein Castle in Germany commissioned by Ludwig II of Bavaria, an example of 19th century Romantic architecture. Notice the standard 2 x 4 dot blue Lego brick. This will give you an idea of how small the nanoblocks are.
What I'd really like to get is this little cutie.