In their own words:
"Don't worry. In fact, don't bother thinking about it. We only update the PageRank displayed in Google Toolbar a few times a year; this is our respectful hint for you to worry less about PageRank, which is just one of over 200 signals that can affect how your site is crawled, indexed and ranked"
If you want to find out first hand how to get your site optimised and indexed on Google, then I would highly reccomend visiting the Google Webmaster Forum.
Even if you don't do your own SEO, it's still makes good business sense to give yourself a basic grounding, so you can evaluate any outsourced SEO work you are having done. From personal experience, the quality of the "experts" varies greatly
