Look for a DoFollow blog list and start writing comments. Remember to read the site before posting and post relevant comments to avoid ending up in the spam pile.
I think you just rent them... actually if you contact people even if they don't have paid text links currently and ask what it would cost, most people would accept the money. Of course existing networks like Direct-Link-Ads and others is a lot easier. Eric
If you post a quality comment on such good pr site then you can get a strong link to you site. They only approved some best review. Or doing five comment on pr 1 sites will also give some good result.
It is not easy to get free backlinks from PR5 and above sites. My suggestion is that find high pr site and ask the blogger to link exchange with you. In most cases it won't happen. But, nothing wrong by trying right?
Yeah thats true, the odds of getting free links that high would be tuff. I think you should focus more on high traffic sites and good content rather then pagerank. pagerank can change anytime.
Try Fast Blog Finder software. It will find many DoFollow with high PR blogs for you. And the best is, that they are releveant.
Just writing extremely good, attractive or controversial content, sooner or later high pr site will give backlinks to you
This is probably the best suggestion. You can also try to exchange links but you must have a good website with a good PR (at lease PR3 or PR4) and maybe you'll succeed. If nothing works you can always buy some links