There are a lot of tools that try to predict the Pagerank for your website. Are they reliable?
I'm sure they're not as i tested them with alot of websites. Most of the predictions where wrong and only google knows how they're algorithm works.

From my point of view pagerank prediction tools are absoultely not reliable but they are still fun to use. Here are some:

http://www.iwebtool.com/pagerank_prediction
http://link.ezer.com/tools/pagerank_prediction.asp
http://www.rustybrick.com/pagerank-prediction.php
http://futurerank.com/rank/