In May 2005, I used 1,702 pennies to make a portrait of Abraham Lincoln. (I thought it was cool that old pennies were darker than new ones, and that I should do something with that.) 

Since creating the portrait, I've been asked to appear on The Late Show with David Letterman (they wanted a portrait of Biff Henderson made out of pennies), on an MTV reality show, and in an L.A. art gallery.

Several others have recreated the idea, and even turned into a toy for kids.