Although most search engine optimizers agree that the green PR display has few to do with the real performance of a site in Google, many webmasters still focus on sites with a high PR.
When a search robot visits a webpage URL, the server redirects the spider to a page with high Page Rank. Google bot assigns the high PR to the webpage with the redirection because it thinks that web pages are the same.
When a user visits the page URL, the server does not redirect the surfer. That means that the visitors see the page of the faker and the Google toolbar displays PR of the redirected page. Google doesn't like cloaking, so you risk losing your rank if you use the method above.