Once you’ve conquered your fear of static electricity and successfully built a kick ass custom PC from the ground up, making the jump to custom electronics isn’t all that intimidating. The open-source Arduino microcontroller breaks down the entry barrier even further. Flexible, powerful, easy-to-use and licensed-to-alter (under Creative Commons Share-Alike), the Arduino is the linchpin behind scads and scads of nifty DIY electronics projects. And hey! It just so happens that we’ve gathered 25 of the coolest, craziest, and most useful Arduino-powered projects in this gallery for your viewing – and building – pleasure. Mind-controlled Nerf guns, anybody? No, it’s not black magic. It’s the magic of Arduino!