Astronomers have discovered a rocky planet orbiting Gliese 876 star, just 15 light years away (also: Slashdot story, Berkeley press release).
The planet has 7.5 mass of Earth and radius twice as Earth. It's distance from the star is just 0.021 astronomical units (AU).
It's smallest planet discovered so far and third in Gliese 876 system (there are also two Jupiter-like planets).