Sorry if this method has already been shared. I have a website dedicated to Seo and often I receive e-mails requesting a link exchange. What they offer me is 2 links to my website from PR3+ domains in exchange for a backlink to one of their "other" sites. Since they link back from 2 different sites they are not pushing away their clients to their competitors (me in this case). So what you can do is buy 2 domains with PR that are somewhat relevant to the niche you are in (keyword in domainname), setup a simple informational site and start e-mailing webmasters in your niche and offer them 2 high PR backlinks in exchange for 1 backlink to your money site. I recieve these kind of emails almost weekly so I bet it works.