Sharpie, the, erm, sharpie company, has just reinvented the genre. Instead of making an erasable pen, it has made a non-erasable pencil. How's that for smart thinking?

Their newest creation is the Liquid Pencil, a smooth-writer that gives you a few days to erase your work before it becomes set in stone. Think of it as the yin to the erasable pen’s yang.

FiftyThree has been taking preorders of Pencil as an in-app purchase directly i n the Paper iPad app as well as through its website. It’s selling a graphite model for $50 and a walnut model for $60.