I hadn't heard of Shepard Fairey until I saw the iconic poster of Barack Obama that has become a cultural phenomenon. Los Angeles-based street artist, graphic designer, and illustrator, Shepard Fairey's "Hope" and "Progess" signed/numbered posters are selling for thousands of dollars on eBay.
His work has a very vintage feel to me, using beautiful colors and graphics. "Utilizing currency motifs and a Norman Rockwell aesthetic, Fairey employs the graphic language of the subjects they critique. Blending Art Nouveau, hippie, and revolutionary propaganda styles, he celebrates subjects advocating peace."- Kellis Landrum
You can read an interview with the artist here.