This currency manipulation project is created by James Charles. Charles is showing an exhibition with collaboration of artist Akira Beard at the Shooting Gallery in San Francisco till June 4, 2011, Called American Iconomics. He has used many celebrities' faces to feature pop culture on currency.
"Altering currency in this way also poses questions regarding the true value of paper bills, something made with seemingly insignificant materials – that somehow fuels our country’s evershifting economy, and ultimately impacts living conditions around the globe. James has put a wrench in the recirculation process by claiming his role as an artist, and declaring these specific bills are not currency, but art objects."
Have a look at his work below. The footer of bills give clues about people printed on. Also watch: Hundred dollar bill defacements