Have you ever fantasized about traveling back in time a few hundred or thousand years and giving civilization a boost? Here's a poster for you in case your fantasy comes true. You can even get it on a T-shirt.
UPDATE: Some commenters have kindly pointed out that this poster was created by Ryan North of Dinosaur Comics. Thank you, kind commenters!
Mark Frauenfelder is the founder of Boing Boing and the editor-in-chief of MAKE and Cool Tools. Twitter: @frauenfelder. His new book is Maker Dad: Lunch Box Guitars, Antigravity Jars, and 22 Other Incredibly Cool Father-Daughter DIY Projects