The surface pressure of Pluto is around 0.3 Pascals, or to put it another way, in the region of 3 microbars. By comparison, Earth's surface pressure is 101.325 kiloPascals.
Pluto's tiny size makes for strange reading if you are more used to dealing with more terrestrial statistics. Pluto's gravity is 2.2ft per second squared, meaning a person who weighed 150lbs on Earth would weight only 12lbs on Pluto.
Pluto's escape velocity is also much less than Earth's, a mere 2,751mph as compared the speed a craft needs to reach to leave Earth's gravity - 25,030mph.
We'll learn more about Pluto when the New Horizons probe reaches this distant world in 2015 (it's been travelling since 2006!) This film explains more: