Ask HN: Is it possible to turn this into a Viral Campaign?

I have a guy who is willing to sell advertising in the form of permanent Tattoos (see: http://www.checkoutmyink.com/tattoos/billythebillboard/my-tapinko-com-tattoo-advertisement ) He will tattoo anything, anywhere, and the price is relatively inexpensive (about $125 a square inch). He is very flexible with his pricing and is just looking to gain some added exposure and make some side $ to help support his family. Billy 'The Human Billboard' is also a humanitarian at heart. He has donated hundreds of pints of blood, pounds of platelets, and even gave a kidney to a stranger he met on Matchingdonors.com I would love some ideas on what you think would be the best way to use this guy to get something viral going... Billy has also given me the ad space on the back of his other calf. Given I am not going to use it, maybe I can help reward the best idea with this space for your logo/venture. Is this even a good idea? Thanks, -P