3-D printer

You can stop pounding on that anvil now; steel fabrication has moved onto the web. Shapeways, a company that made its name offering custom 3-D printing in plastic and resin, will now print your designs in stainless steel. All you have to do is upload your brilliant CAD design (or pick from a range of stock items). Shapeways will print it out in cold, shiny steel, and mail it to you.

3-D printing may soon expand beyond the small scale. In 2010, the world's largest 3-D printer will build the Radiolaria Pavilion, a 10-meter-tall structure in Pontedera, Italy. Made out of sandstone, the building will be printed one 5-10mm layered sheet at a time.

As a child, Hod Lipson lost Lego pieces constantly. Now the 39-year-old director of Cornell University's Computational Synthesis Lab can build replacement parts on the spot. Completed last year, Lipson's fabrication machine, called a "fabber," can print thousands of three-dimensional objects, everything from toy parts to artificial muscles, using dozens of materials, including PlayDoh, peanut butter and silicone, by following simple directions sent to it by a PC.