Google Page Rank Algo is Old as Dirt

It is not quite as old as dirt, but the algorithm has been around for some time.
Many of the algorithms commonly used today for sorting and searching are also quite old.

Tag Clouds are cool things to discuss and they make for nice assignments for students.  The discussion of Tag Clouds gives students a better idea of how page ranking works.  I have my students create a basic tag cloud program and they really enjoy it.