There are at least two bands that go by this name, one British and one American:
1) South is a London-based trio of talented multi-instrumentalists that defy any one label. Rock, electric, acoustic, folk and orchestral only touch the surface of South's repertoire. Their first album, From Here on In, was released on Mo'Wax. Between this and the next album they supplied the score to Sexy Beast along with UNKLE. Their sophomore album, With the Tides, was released domestically in the United States on the Kinetic Record Label in 2003. The release of their third full length album; 'Adventures in the Underground Journey to the Stars' in 2006 has only expanded their sound while taking on new challenges by mixing and producing their own tunes in their very own studio.
2008 brings more changes to South with a move to Bluhammock Records. Scheduled to be released in April, "You Are Here" showcases some redone older tracks as well as breaking new ground.
Their track "Paint the Silence", from From Here On In, quickly became a hit after it was played in the ninth episode of The OC in Season 1. The episode was entitled "The Heights".
2) South is also the name of a Virginia-based drone/post-rock group that released a self-titled album in 1999.