Rob Cockerham went around his neighborhood and estimated how much his neighbors were paying in electricity charges for their Christmas lights. For the house above: 2,135 watts = 26¢ per hour.
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