I always liked to build stuff out of Lego or other building sets when I was a kid and I still build stuff with my kids today out of Lego. I also now know why my parents hated Lego so, but that is another story. A new building set perfect for geeks young and old called Nanodots is available.
Nanodots are small magnetic spheres that can be used to build all manner of shapes. The Nanodots come in original, black, silver, and gold colors with each set having 216 spheres. The sets also ship with a carry pouch and instructions.
The building sets vary in price with the original set being the cheapest at $29.99 and the gold the most expensive at $39.99. You need a ton of these things too; some of the sample things that the Nanodots site shows have hundreds and hundreds of the dots in the design.