Zenit publishes an article written by Cardinal Cláudio Hummes, prefect of the Congregation for Clergy, on "The Importance of Priestly Celibacy" that was published in the Italian edition of L’Osservatore Romano. The article is very good and covers both the Apostolic origins and early history of celibacy in the Church along with its theological dimensions. The article is really a good short treatment on the subject to counter such nonsense as the Church supporting celibacy in the 1200’s because of property inheritance problems.
One thing that never fails to make me laugh is any mention of The Synod of Elvira (300-303?) . Elvira just does not bring to mind celibacy for me.