Most of the experts are correct that pr depends upon quality back links.don't waste your time and money in directory submission except dmoz type. find some good content base links which would be good for you. cheers
In order to improve your site's PR, you need to get quality and relevant backlinks. Try to get some backlinks from high PR pages.
I think you need for a quality backlinks, try to make an exchange links to a relevant sites this would help you get a high rank. Not only PR1 would be expect. :0
go back and check your backlinks, is it from high page PR? or is it from a high site PR but the page where your links are from don't have PR. This is common with directories. you also need to check whether the links are no follow or do follow. This is common with blog commenting. PR, SERP placement, traffic, conversion rate are different things. They are worked at differently. Just because PR is one of Google trade secret doesn't mean its not important. But you are right, PR by nature favours old pages.
at the beginning i use linkreferrals for backlinks. but its too time consuming and useless. my PR did increase from 0 to 2 but i suspect its not caused by linkreferrals. i got some quality backlinks as well. for the recent PR update, i just got 4 to 5 quality backlinks from a high PR forum. and that is enough to bring my PR to 3.