tedster - 5:19 pm on Aug 6, 2011 (gmt 0)
One important factor is that PR is also voted around inside the site itself. If you have lots of strong backlinks to one page, then the pages that page links to get a share of the PR even if they have no backlinks themselves.
So artificially "building" backlinks to every page on a website is not wise - in most cases it is an obvious attempt to manipulate Google. A natural backlink profile to a website would not have backlinks to every page.
Much better to have good content, get whatever freely given and editorial backlinks you can, and let your internal linking pass that PR around the site.
Also note, the original PR formula has long been changed from the original patent... several times and including within the past year, in fact. We don't know all the specifics about how PR is now scored, but we do know things have changed.