QUOTE(johntoh @ Dec 14 2009, 12:11 PM)

PageRank is only one of numerous methods Google uses to determine a page’s relevance or importance.
Google interprets a link from page A to page B as a vote, by page A, for page B. Google looks not only at the sheer volume of votes; among 100 other aspects it also analyzes the page that casts the vote. However, these aspects don’t count, when PageRank is calculated.
PageRank is based on incoming links, but not just on the number of them – relevance and quality are important (in terms of the PageRank of sites, which link to a given site).
yes, some website owners are trying real hard to make their web page rank higher. thanks for the info john.
that's what SEO and link builders are doing to increase its PR numbers.