Sometimes web pages disappear. Older trails often traverse pages that have long since gone. We need a way of preserving the pages of a trail. Fortunately we can enlist the help of "The Way Back When Machine" at http://archive.org. If a page no longer exists we link to the archived version of the page stored by The Way Back When Machine. Search engines like Google and Yahoo only index the most recent version of the page. Trexy enables you to search deeper into the past with the help of The Way Back When Machine!