When, in 1595, the Dutch spectacle maker, Zacharias Jansen, placed two lenses, one concave, one convex in alignment, he was able to magnify a small object, thereby inventing the microscope. For the first time we were able to examine the structure of matter in close-up. Which brings us to the USB microscope, the great, great, great, great, great, great grandson of Jansen's device. This smart USP-powered instrument lets you zoom in (from 20x to 200x) on any object you fancy. And thanks to its accompanying software you can record your findings as photos and videos on your PC. Hold it like a pen or pop it on its smart little desktop stand. And, since yesterday many people have started using £20 notes as loft insulation, it's cheap.