This piece was posted on Pink Tentacle in March:
Do boomerangs return when thrown in zero-gravity? Japanese astronaut Takao Doi will soon find out by throwing some around inside the International Space Station. When the Space Shuttle Endeavour launches on March 11, Doi will be carrying a pair of paper boomerangs presented by Yasuhiro Togai, a 2006 world boomerang champion and space enthusiast from Osaka. Togai, who long wondered how boomerangs would fly without the downward pull of gravity, suggested Doi conduct boomerang experiments in space after they met several years ago. Doi agreed, and Togai taught him how to throw. Togai believes the space boomerangs will spiral up and away without returning, but he says he is looking forward to the results.
And the video above displays the result. Gravity is not the reason that boomerangs work. (Thanks to Kevin R. for the tip!)