it's not the number but the quality of those sites and the content that they provide in relation to yours... The math is more complicated than just a number...
You don't any backlinks for become PR 2. Also if your host update time is better than 95% you can get PR 3 without backlink. I have a lot of domain like these. Cheers, mirTurk
You generate PR the same way you generate traffic: quality backlinks due to quality content. Period. There is no way a site can achieve a PR of 3 (or any PR) without some form of backlinks.
yeah, how did you get the PR 3 without any backlinks? Backlinks is very important to achieve high PR. Can you show us the URL?
To get a PR all you need is a bunch of quality (meaning quality content, websites and high PR on the website) backlinks and time. Easier said than done.
that has a link from 1 pr3 page site, according to yahoo site explorer or by using the link operator. In other words get links, submit to directories
with one link ok. I have also domain with links which haven't got PR values and again same result. So being PR 3 is not important and very easy.