3-D printing is all the rage. You can hit a button on your computer, which sends a file to a printer, which produces a small 3-D object out of plastic. Want a more hands-on way to make things? Enter the 3Doodler: the pen that turns you into the 3-D printer.
It's made by the startup Wobbleworks and is a $99 fat pen, not unlike a hot glue gun. As you move your hand, it leaves a thin trail of cooling, solidifying plastic. Move it around with a plan, laying down string upon string, and an object starts taking shape. The plastic costs $10 for packs of 25 sticks.