Robert De Niro
Digital painting - done in Photoshop with a Wacom Bamboo.
See it in more high res: http://5ic.deviantart.com/art/Robert-De-Niro-338240887
See some steps of the progress: http://www.behance.net/gallery/Robert-De-Niro/5964083
Rebound: http://dribbble.com/shots/1107611-Robert-De-Niro-Step-by-Step