A couple months ago, street artist/designer Shepard Fairey debuted his limited-edition Barack Obama prints on his Web site. Like everything else Fairey has done (including honest-to-goodness marketing campaigns for corporate giants Pepsi and such) the series of Obama posters took inspiration from Fairey’s “Andre the Giant”/”Obey” anti-campaign he’s famous for: shadowy, graphic, three-tone images that have influenced every darn last guerrilla marketing effort for more than a decade.

Now it seems Fairey’s pro-Obama art has created a new movement. This week, the Obama campaign announced it will be selling donated Obama-themed artwork at “Artists for Obama.” Currently, the only artwork available there is Fairey’s “Change” poster for $70, even though eBay sellers are listing some Fairey posters for more than $2,000.

And while Fairey’s street-art images are popping up in cities everywhere, they’ve also inspired other artists to start some guerrilla marketing of their own. This Obama street-art group on Flickr lists more than 65 images of unique Obama artworks spotted on sidewalks, garbage cans, building sides, street signs and more in nearly every city. That leads us to this question: The Flickr site: Viral marketing of its own, or simply a documentation of a movement? You decide.