From the experts:
Keturah, the Old Testament name of Abraham's second wife, is a possibility for anyone seeking a truly unusual and interesting biblical name; certainly a lot more distinctive than that of Abraham's first wife, Sarah.
Keturah bore Abraham six sons, who were characterized by one historian as "men of courage and of sagacious minds." Through them, Keturah was the ancestor of sixteen tribes. In the eighteenth century it was believed by some that Keturah was the ancestor of African peoples.
This is a name not readily found in popular culture, though there was a character named Keturah on the TV sci-fi show Stargate Atlantis—but he just happened to be male.