The mesofacts site is an interesting one. The concept seems related to the "half life of information" which has over 7 million hits on Google http://www.google.

The mesofacts site is an interesting one. The concept seems related to the "half life of information" which has over 7 million hits on Google http://www.google.com/search?q=half+life+of+information http://www.google.com/search?q=half+life+of+information [Caution: you can lose a couple of hours on a Sunday afternoon following these links]