I honestly wouldn't bother doing it all. The publicly available [toolbar PageRank is only one of 200+ factors][1] Google uses and it doesn't necessarily reflect where your page will appear on the search results pages. It's not updated very frequently either (every few months), while the actual search results are updated daily. At best, it's a not very useful barometer of how Google views your site. 

Beyond just basic SEO best practices, you're far better off focusing on improving your website's usability, content, and actual conversions once people get to it than by wasting time checking PageRank constantly. It's important to remember the purpose of your website's existence. If it's to make you money, focus on improving that, not on improving PageRank. PageRank doesn't directly make you money. If you're concerned about getting more traffic, use social media or advertising. PageRank doesn't directly bring you more traffic.

All that said, this might be what you're looking for if you want to [waste your time][2].


  [1]: http://sphinn.com/story/74952#c54521
  [2]: http://pagerank.bthomson.com/