The quantified self movement's gaining steam, with companies creating all sorts of gadgets to track our activity levels, sleeping habits and even what's going on inside our heads. Melon's an EEG headband that taps into your brain's inner workings to show you how well you maintain mental focus. We actually saw Melon's prototype predecessor last year when it was called Axio, and while this new band packs largely the same components, the design's
