Pencil Caps That Serve As Sharpeners
All modern pens (like BIC) come with an attached lid but no pencils do. If you could attach a lid to a pencil by inward compression or grooves in the pencil then it could have a safe lid that serves as its own pencil sharpener and the lid could always reattach after each use. You also wouldn't stab or poke your eye out like mom always says to watch out for. This would work on any pencil from carpentry to grease pencils etc.
Reward: A set of colored pencils with this device.