I was just listening to this video a little while ago...

http://fora.tv/2009/02/24/Dan_Roam_Back_of_the_Napkin#chapter_01

(It may be necessary to click on "Full Program" and then on "Introduction" in order to hear the whole thing.)


The guy talks about how people come up with ideas using pictures. He described how some guys were in a bar and one of them drew a primitive sort of a curve on a napkin and explained that it showed how tax revenues could increase if taxes were cut. The other two guys that were with him were Rumsfeld and Cheney. They took the napkin to Gerald Ford, and the rest is history.

Figures it would be an idea someone came up with while drinking in a bar.