You can find the full instructions here, but you should probably take note of a few things before you get your hopes up.
First off, the method relies on a JavaScript tool that only works in the Google Chrome browser, oddly enough.
Secondly, you can't use any old 3D printer to make a proper 3D printed plate. MakerBot 3D printers are out (Pseaton specifically mentioned that), but he was probably thinking of all desktop 3D printers (you know, the type that lets consumers play with 3D prints without providing that high a detail level).
You may as well get a high-end Shapeways model, or just contact a 3D printing store/service to do the legwork.
It's not that hard to make the 3D printable files, especially with the detailed, step-by-step instructions. The website isn't called “Instructables” just for kicks after all.
Whatever image you choose, the graphics actually translate pretty well into the pixelated image of the block printing plate. It's your choice whether you use the plates as they are meant to, or just paint them and hang them on a wall.