I recently came across some original artwork by Steve Thomas. He designs a variety of vintage and propaganda style posters that highlight everything from space travel, battling sea monsters, and scenes from the movies. He also created a cool series of vintage themed Star Wars travel posters.
These office propaganda posters are what first caught my eye. It's a fresh perspective on those familiar workplace signs, playing on a style often used for much heavier themes. You can view more of Steve's work on his site HERE.