A lot of people a while back were talking about how when you go to the www and non-www version of their site, you get a different PR. Here's a quick fix to that, which uses .htaccess to permanent redirect the page to the non-www version, so you don't need to worry about that pesky www version having a different PR. Note that you can also go from non-www to www but that's just redundant, imho...
(In your .htaccess)
(In your .htaccess)
Code:
RewriteEngine On
RewriteCond %{HTTP_HOST} !^site.com$ [NC]
RewriteRule (.*) http://site.com/$1 [R=301,L]