The European Southern Observatory (ESO), which owns some of the most sophisticated Earth-based telescopes (all them located in Chile's Atacama Desert), has detected at least five Neptune-sized planets orbiting star HD 10180 in the constellation of Hydrus. Other two smaller planets have been detected as well but with some uncertainty, one of them orbiting very close to the parent star and measuring 1.4 times the mass of Earth.
The finding represents the first time a planetary system so similar to ours, with planets organized following the Titus-Bode law (each planet is roughly twice the distance of the one immediately closer to the Sun) and with almost circular orbits. It is also sign of a new phase in the exploration of extrasolar planets, not anymore searching for individual planets as much as for whole planetary systems.
This has been possible thanks to the HARPS or High Accuracy Radial velocity Planet Searcher, a highly sophisticated spectrograph. Other 75 exoplanets have been discovered with this instrument.
The details are explained at ESO's site. BBC also has an article on this discovery.