Voluntary Sponsorship of Linux?

shift8key asks: "Last year, a friend asked me whether I would sponsor his NASCAR race car. The sponsorship came cheap and I decided to do it. Since I did not have a commercial message for my business, I had him put 'Linux.org' and a penguin on the hood. He had more inquiries about it than any other message on his car. My community phonebook called me to ask if I would repeat the message there, and I think I will do it. Have any Slashdot readers ever done any voluntary sponsorship of Linux? If so, what experiences did you have?"