What is the significance of the white stone in Revelation?

He who has an ear, let him hear what the Spirit says to the churches. To him who overcomes, I will give some of the hidden manna. I will also give him a white stone with a new name written on it, known only to him who receives it.  Revelation 2:17

Jesus spoke to the church in Pergamum and said said that everyone who believes, overcoming the temptation of evil in their time, will receive a white stone.  What is the white stone?

The meaning of this is unclear.  It cannot be taken literally, since why would God hand us a white stone with a name on it that we have to carry around for eternity?  There have been some historical possibilities suggested throughout time that the stone could symbolize.

Token of Innocence - A white pebble was placed in a ballot box by a Greek judge pronouncing a sentence of acquittal (a black pebble indicating condemnation).  Jesus is saying by giving you a stone, you are "not guilty."

Token of Privilege - A tessera was given at Olympic games to the victor with subsequent attendant social privileges.  Jesus is saying by giving you a white stone, "you win!"

Token of Initiation - A token of initiation into the cult of Asklepios.  Jesus is saying "welcome to the club."

Good Omen - Reflecting the practice of a person who placed a white or black pebble for each happy or unhappy day into an urn. At his death, the colors were totaled to rate the happiness of his life.  If Jesus hands you a white, it summarizes all the goodness you need for your future.

High Priest’s Headdress/Breastplate - “One explanation links the white stone with the platelet of gold that graced the high priest’s headdress (Ex. 28:36-37). The words inscribed on it were ‘Holiness to the Lord.’ According to this interpretation the overcomer will wear a headdress with a precious stone, on which shall be engraved the new name which belongs to the new Lord of the new kingdom, a name equivalent in value to that of Jehovah under the Old Testament, which no one but the high priest knew how to utter.”  Jesus is saying with this white stone "you're holy."

Urim and Thummim – stones hidden on the breastplates of priests used to make decisions about someone’s fate.  Jesus is saying that your fate has been determined, "you receive heaven for eternity."

White means righteousness.  Stone means a guarantee/promise.  A new name means a new identity.  Together it could mean that when we die we are promised righteousness in heaven with our new identity in Christ.