Self-sharpening pencil

I like this hi-tech mechanical pencil from Japan because it sharpens itself so that it produces a very consistent line, no matter how long you use it. The Uni Kurutoga Advance ($9) contains a novel mechanism that rotates the pencil lead each time it touches the paper, so that it wears evenly and maintains a uniform point. So clever! It currently is only available for very fine 0.5mm lead. — KK