If you're a fan of Arduino's tinker-friendly approach to computing, you'll be glad to hear that it's now extending that open philosophy to 3D printers. The company has teamed up with Sharebot to unveil the Materia 101, a small (5.5 inches by 4 inches) printer that's built to be both friendly to beginners and very accessible. You can modify the code on the underlying Arduino Mega mini-PC, of course, but you also have access to the full schematics of the printer -- you can upgrade it or even make your own, if you have the know-how and parts. Arduino hasn't said when it plans to ship the Materia, but it'll be available both as a build-it-yourself kit (priced under $800) and fully assembled (under $1,000).