same here, its great my art site is only pr1 - pr2 and its up playing with the big boys with much higher pr.
Here's an article on Google PR, how it's calculated and what you can do to improve your PR. Google Page Rank Explained The article was based on an original article by the Google founders.
Does PR go back to N/A or 0 mean Google killed all information from your site what they had in their servers?