Do an entry of a website in PR0 directory has any effect on the PR of the website?? mean if i submit my website to 100 PR0 directories.. will it raise my websites PR?
There is a table of calculations somewhere. You can turn PR10 just from PR0 links. Thats how the algorith works. You would probably need a billion PR0 links though.
A site shows as a PR0 on the Google toolbar is not necessarily a PR. The toolbar PR is already out of date when it comes out. Google uses updated information for its PR and ranking purposes.