Get high pagerank backlinks easily with Digg.

First of all go to Digg and signup for an account and scroll back to the older stories relevant to your niche. Diggs that have been dugg like more than a year ago or older. Click on the comments section for any digg post that has less than 30 comments.
Use a pagerank checker to check the pagerank(Older posts usually have a higher pagerank).
Post a comment and put one of the links in the comment.
Now you have a high pagerank dofollow link.