This design has recently been made popular by the TV show "Charmed", where it appears on the cover of the Book of Shadows. The number three was significant to the early Celts, who used it to represent the three-fold nature of the Goddess (Maiden, Mother, and Crone), or the Christian Trinity (Father, Son, and Holy Ghost).
Quote of the moment: ...when all government... in little as in great things, shall be drawn to Washington as the centre of all power, it will render powerless the checks provided of one government on another and will become as venal and oppressive as the government from which we separated. Thomas Jefferson, 1821