Looks like Google might be in the middle of a new Page Rank update, which is very important for those of you concerned with SEO (Search Engine Optimization). These updates usually happen every 2-3 months and can greatly affect how a site is viewed by the search engines, especially Google. For details on what Page Rank is and how it can affect you, Darren Rowse of Problogger.net has written a very good Google Page Rank introductory article.
Although it can take several days for the Google Page Rank update to fully propagate, there are some online tools that might be able to give you an advance idea of your site’s Page Rank. This particular one will hit many different Google servers at once in the hopes that some of the servers have already been updated. If you see discrepencies between the results, this means your site’s Page Rank has been changed but that change has not fully propagated through all the Google servers.