We all know the story of Edward Longshanks stealing the Stone of Scone/Destiny and taking it to England. If you don't, you should. If you do, you might know what is believed to be the story.
I've been reading The Story of Scotland by Nigel Tranter, and in that book he presents his theory/belief the stone was given to Aonghas Og, the Lord of the Isles (or Islay), to prevent its being taken by the auld enemy.
I must confess to be unaware of this viewpoint but it seems he is not alone in that belief. Here is a link to a Wiki (the source of all knowledge ;-)) article discussing the Westminster Stone Theory. According to the theory, the stone was probably hidden on an Eilean Sgitheanach (the Isle of Skye).
Personally, with no evidence to support my belief, I like to imagine the stone was taken to the powerbase of the Lord: Finlaggan!!! If it's there, I wonder how close I was when I visited in May of 2009, and again in May of 2010?