I agree getting 100 backlinks per day is unatural if ur website is out of the top 1000 alexa rank. You can easily get blacklisted if u get thousands of spam links.
Google usually updates PR once per quarter so everyone expects it has already happened in early July.
You cant build pr without building backlink pointing to them. Always use blog comment and forums posting to gain those backlinks
I'm with the group on higher PR backlinks. I'm also with Ken on the compelling content. That's what gets other quality sites to link to you, when you provide value to them (free content or service)and they will link to it.
I have a bunch of quality Backlinks from software I downloaded for my mac. They list out which blogs and etc I should post on.