This one's for Aaron.
Sharpie has entered the game of "bust that ontology" with a a "liquid pencil." (As I understand it, there are other products titled "liquid pencils" that aren't graphite-based and aren't erasable like a pencil. And yes, it's ready for purchase.)
So... is it a pencil? Or a pen with graphite ink?
Philosophers? Any help?
[Via Rob Beschizza. Title references Hamlet, if you weren't sure.]