Matt from Google answers some questions about Page Rank -
http://www.mattcutts.com/blog/more-info-on-pagerank/

And Google has a new "test" search site - remember many things they test they end up implementing so go play with it.
Article about it -
http://blog.searchenginewatch.com/blog/061002-192616
The site - http://www.searchmash.com/