I have seen quite a few blackhat sites using this technique, however they usually use sites that get their search results through the big search engines here is an example
While only G knows the true PageRank algorithm, it is believed that the method is still based on their original patent. And in that case it just would not work. If there is only one link on a page, all PR is transfered thru that link. If you add another link, each one transfers only half. ...that means if you link to your site, you'd get X PR. If you add another link to google page, you'd get X*(0.5+0.5*0.1) (assuming there are 10 links on that google serp) that is X*0.55 of what you could get. (this calculation was simplified)