From smartphones to digital cameras, our gadgets often live out in the elements. But unlike a 4x4, dirt on tech isn’t a badge of honor. Even those that don’t see the light of day, like a computer mouse or a flat screen, can develop a layer of grime that slowly degrades performance. Of course, each gadget's specific cleaning technique varies, so it's best to consult the manual or brand's website before going too far. Here’s how to keep it all clean.