I know moderation and diversity is key, but I am building a huge link network but I have some concerns on PR0 sites.. I know google updates page rank from time to time so a quality PR0 site could be a PR1+ site in a matter of months. But say for a new site, would google frown upon receiving links from PR0 sites? The reason I ask is when harvesting, I noticed the majority of the sites that I am able to post to are PR0, I then go through them and filter out the ones that are overly spammed and only keep the ones which I consider "clean" but Im trying to figure out how much is to much. Any insight is much appreciated.