I’ve always loved retro travel posters, like the classic “flat” WPA travel posters of the 1930’s. I particularly adore when the style is applied to space and science fiction themes.
Recently artists at NASA’s Jet Propulsion Lab came up with an “Exoplanet Travel Series”, highlighting worlds recently discovered by Kepler and other extraterrestrial probe programs. As a government-funded body, NASA has made the posters publically available and free to download at high resolution print sizes.
Astronomer and artist Tyler Nordgren has drawn several travel posters in a “Planetary Parks” series, including Europa and Mars:


Steve Thomas also has some excellent travel posters:


You can buy prints of Steve’s work from the Intergalactic Travel Bureau.
Finally, Justin Van Genderen has created a series of excellent travel posters from science fiction films, including Star Trek and Star Wars:

You can buy some of Justin’s work at his online store.
Thanks to Bob Dow for the inspiration behind this post.