Every six years, the names repeat. However, if the storm was particularly violent or destructive, the name is taken off the list. That way, when someone mentions Hurricane Camille, most people know they mean the storm that hit the Mississippi Delta in 1969.
Sometimes, names are specially changed to suit the area of the world that is hit. When hurricanes approach within 1,000 miles of Hawaii, for example, they are given Hawaiian names.
Forces of Nature: ThinkQuest 2000 (Team #C003603)
http://library.thinkquest.org/C003603/english/hurricanes/hurricanenames.shtml
Once more modern hurricane tracking systems began, scientists found it necessary to identify each storm. Beginning in 1953, the first storm of the season was given a woman’s name starting with the letter A. The second storm was a woman’s name beginning with the letter B, and so on. It wasn’t until 1979 that men’s names began to be used.