Get the quality backlinks for your blog and update with content regularly. Drive more traffic to the blog.
You can try comment on high PR blogs, or from Forum's signature But it's only for short-term, in long-term, you must build a good blog or website that people will link to you. It's better than running around and pasting your link
PR means nothing unless you are looking to sell links imo. Just concentrate on improving serps and making the dollar - that's what you're in it for right?!!
Backlinks may helpful. do work on off page optimization, like forum posting, article submission and social networking sites are good.
Maybe it need time and your efforts. The PR will update with a long time and you must have a good site at the same time when updating,
Quality backlinks depends on your content quality, if your content is good you get quality backlinks.
You have to add some high PR external and more content-related links to transfer to your site! The 'PR' thing is just a measurement tool utilized by the SE boss GOOGLE, but it can not override other measuement.