The toaster has just five components: rebar, part of a cinder block, wood, a wire and fasteners. I'm not exactly sure how he gets the rebar hot enough to toast, but I imagine power travels through the rebar, and the resistance makes it heat up. And he seems to be in Israel, where outlets pack a 230V punch, which would help.
One less cheap burnt-out toaster headed for a landfill. [FastCoDesign]
Image: Adi Zafran