The International Space Station up there is currently widely used as a laboratory to perform experiments under weightless environments without gravity. This video on Youtube shows a few of these (probably not so top secret) experiments done at the station, investigating the effects of waves in a sphere of water, bubbles in a sphere of water, as well as an antacid tablet reaction with a sphere of water.

The experiments themselves are only high-school leveled labs when performed on Earth, but when performed in space, it just gets that much more fascinating.