There are more means of personal expression these days than at any other time in history, but whether you choose blogs, message boards, graffiti, tattoos or even traditional artistic mediums, it's always more fun if there's an element of danger. One of the most cost-effective forms of dangerous personal expression -- that's just as illegal as graffiti -- is currency defacing.

In a world where a $10,000,000 bill exists, it's clear money is worth less than the paper it's printed on. This makes the canvas ripe for use as a personal billboard. And if you get things wrong, you can always just spend it (as long as your artistic project hasn't destroyed it). To see what others have created, check out some of the most priceless examples of defacing green in the gallery below.

Personal Messages on Money

    Why so serious? Because we're all losing about ten thousand of these a day lately, that's why.

    denoted.com

    The artist will need that dollar to buy some new markers after this project.

    listoftheday.blogspot.com

    We liked Donnie Darko, too, but that's just creepy.

    This would go better on a $300 bill. But since there's not one, a 20 will do.

    denoted.com

    Nice work on the face, but what is Gene Simmons doing with Starsky's hair?

    listoftheday.blogspot.com

    What, you didn't know that Mario and Luigi had a third brother, Abe?

    listoftheday.blogspot.com

    Wait. We know this one. Duran Duran? Or was it Wall Of Voodoo?

    denoted.com

    You'd be serious too if you had ten dix. Huh? Oh. "Dix" means ten in French. Never mind that last joke.

    denoted.com

    Defacing money is illogical, captain. But it's fun. Now go learn how to spell Spock correctly, nimrod.

    denoted.com

    At what cost? Hmm. Ten bucks? That's just a guess.

    denoted.com