i could say try and get backlinks from .edu and .gov it does a big trick, work less look for high pr site too.
Dont do link exchange, just get one way link. Google hates link exchanges. You can do some social bookmarking, article submissions, or do some blog commenting, etc... Get links from pages that actually have page rank, not just any links. Make sure it's not spam farms.
Finally, 2 of my sites have moved up to PR1. It's odd though. The site I have put most of my effort into is still PR0 and is almost a year old. Another domain which I started in April this year is now on PR1.
You need to build a wide variety of links. I suggest you do some link exchanges with relevant and high PR sites.