SitePageRank.com provides you a Very cool AJAX page rank checking tool and a completely Free tool to check Google PR . Enter a website and it will display pagerank, detect Fake Pagerank, Traffic Rank and BackLinks.
PageRank is one of the methods Google uses to determine a
page's relevance or importance. Pagerank fraud is becoming a serious problem. It
is achieved when offending webistes use a 301 or 302 redirects that point their
sites to sites with a high Pagerank.
Fake PR - Faking Pagerank
Many webmasters buy PR for their site. They find a site that has a PR of 8
for example and buy a link to their site. After a while, your site ends up
with a high(er) PR and you in turn can sell PR or the site in whole;
provided the site you are buying from does not have Fake PR.