3D printing is an undeniably exciting technology — but unfortunately, you need a pretty good understanding of the related software to maximize its potential. Not so with the 3Doodler ($75 and up). This 3D printing pen uses the same ABS plastic as many printers, but allows you to draw anything you like, in the air or on a surface. As you doodle, the pen extrudes heated plastic, which quickly cools and solidifies into an actual thing that you can hold and touch. You're really only limited by your imagination — and your drawing skills.