It's rare to hang on to a pencil until it's been worn down to a nub, but with the Spincil, you might want to.
Ortie Design's whimsical writing utensil comes in purple, green, and yellow and is shaped like a top on one end, so after vigorous writing and sharpening, you can make yourself a fun wooden toy. Basically, the idea is to get your work done so you can play later. While you can arguably spin the top before the graphite is completely used up, it won't rotate for as long, and it'll leave a trail of circular markings in its wake.
[h/t: Lost at E Minor]