You are correct disgust. Thanks. "http://mysite.com" has PR3 and http://www.mysite.com has PR5. I just implemented 301 redirection. And waiting for results. will get back with feedback
don't hold your breath; you will need to wait until the next visible PR update to actually see the PR change. not that there couldn't be advantages in the serps before that.
Page rank and google rank are totally different things. you could have a PR2 and still show up page 1 under the keyword that matters to you.
A great thing to do is to create a Google Sitemap (must get a Google account), put it on your site, verify that you own the site, and then go into Google Webmaster tools and there is an option for Google to see your site as "www.XXXXX.com" or just "http://XXXXX.com". After that...consistency is key. Stick with the way you chose!
So you dont need to redirect if you do this? well, maybe you still have for the sake of all the other SEs, not just google
Not sure for the other SE's, but it's a quick and dirty way to let Google know which you plan to use.