The following is a quote of a Google representative writing to JohnGalt of search engine watch forums:

"The PageRank that is displayed in the Google Toolbar is for entertainment purposes only. Due to repeated attempts by hackers to access this data, Google updates the PageRank data very infrequently because is it not secure. On average, the PR that is displayed in the Google Toolbar is several months old. If the toolbar is showing a PR of zero, this is because the user is visiting a new URL that hasn't been updated in the last update. The PR that is displayed by the Google Toolbar is not the same PR that is used to rank the webpage results so there is no need to be concerned if your PR is displayed as zero. If a site is showing up in the search results, it doesn't not have a real PR of zero, the Toolbar is just out of date"

The full forum thread covers several interpretations of the quote. This is some great information to share with those who may be confused about the meaning & importance of the PageRank shown in the toolbar. Taken together with some of GoogleGuy's comments earlier, SEOs can infer that toolbar PageRank has become quite ancilliary to SEO work.