In a professional studio you'd rely on a set of diffused lights and a curved white sweep to create the infinite white background effect. But the $US149 Cloud Dome works with any lights, even ample ambient lighting, because the translucent white plastic serves to soften and evenly diffuse what's available.
It also works with any smartphone thanks to an elastic strap system that holds it in place no matter its shape, and an included base lets you backlight your subject. Just keep in mind that you're limited to photographing smaller objects, and due to the lack of manual controls on most cameraphones you'll probably still need to do some post-processing in Photoshop afterwards. [Cloud Dome via DPReview]