if you are using mozilla FF then try using SEOBOOK toolbar it not only give info on PR but also many other things like number of yahoo backlinks keyword analysis meta description and more
you can try quirck mozilla plugin. You don't have to enter the url on textbox all the time. As you load the site, it automatically shows the PR and even the your alexa ranking.
*sigh* If only they would add the Google toolbar for Chrome, I would never use Firefox again. But they would also have to add a master password option for Chrome. Lol, I can't believe they didn't add those in the first place. I wonder specifically whose fault that is.
Check this you will get all the backlinks count too with your PR : http://www.checkpagerank.net/ Enjoy