Recently, I needed to find a good visualization of modularity in a presentation. Lego is a nice concept, but maybe a bit cliché. Not if you use this really cool LEGO design tool: LEGO Digital Designer. It is a full 3D design environment in which you can create any LEGO object you want, and even submit it to LEGO to buy a box with the pieces plus a build instruction. It comes with a large online library where people can upload and download designs.
Here is an example of the Empire State Building. You switch on an animation of how the building is built up as the bricks fly in from all directions. Great stuff.
If you are in to LEGO, here are some earlier posts about it. Christoph Niemann uses LEGO to model New York city. This ad visualizes the power of imagination that kids have, but grown ups seem to have lost.