While I'm always in favour of a good sharp knife, what's with all the mechanical sharpener bashing? Mechanical pencil sharpeners are *fun*, as anyone who ever deliberately broke their lead so they could get up to use the one on Teacher's desk well knows. Best thing about pencils, those. If you were lucky, and the teacher was sufficiently distracted, you could make them eat a whole one.
If I owned one, I'd play with it until I'd sharpened away all my pencils. If I had any pencils.