On October 6, 2011 PageRank in 3rd party tool SeoToolbar Firefox add-on on my PC stopped working. Many people start to asking does Google PageRank is dead? The answer is that Google did make a change, they changed the lookup URL for the PageRank value. So 3rd party tools stopped to work correctly.
How to find Google PageRank today?
To find PageRank today you can install Google toolbar add-on. It will work immediately.
For SeoQuake add-on you can find instructions how to fix SEO PageRank following this link: Google PageRank is not dead.
If you have patience you can wait for updates of various 3rd party tools which showing Google PageRank.