I don't really have posters at home, but in my cubicle I have a collection of xkcd comics, Dinosaur Comics comics, and other random printouts. I also have my name in twelve different languages, my favorite quote ("Science is the belief in the ignorance of experts"), my Erdos number (4), and a newspaper clipping of how a former psychiatrist of mine was revealed to be faking his psychiatric degree (and faking a gynecological degree!) and was thrown into prison for 4.5 years and given a 170,000 shekel fine for taking sexual advantage of his female patients.