Update: Google PageRank is NOT Dead
If the words Search Engine Optimisation don't mean anything to you, look away now.
Scott_McLay: Well it looks like TBPR is dead - woohoo no more confusion over its importanceThe PageRank which was visible on the Google Toolbar was always out-dated with that which Google actually used in their calculations for determining where sites should rank in the SERPs. The last confirmed roll-out of Toolbar PageRank was June 27th, 2011. Although many smaller updates had taken place, in particular for new websites and those which had been redirected from others. Presumably those who still made heavy use of PageRank - mostly link sellers or SEO agencies who didn't know better - will now presumably turn to MozRank, a website authority rating by SEOMoz. It may not be completely the end of the story for Toolbar PageRank, however, as some on Twitter reported they could still see PR.
KevStrong: To all the peeps saying that PR is showing as 0 - Mine works fine on Firefox 4.01 but my custom built PHP PR checker does not.