Four-dimensional internets

This video is worth checking out if you've got the time. It shows an application that allows you to select portions of a web page and turn back the clock, giving you a glimpse of what the page used to look like. I suppose in the future the whole internet will be constantly archived, and it will be common to specify a date range parameter in, say, a Google search. The thought is scary from the standpoint of trying to erase something stupid you said on the internet, but awesome from all other standpoints.