Setting the preferred domain

Setting the preferred domain: "The preferred domain feature enables you to tell us if you'd like URLs from your site crawled and indexed using the www version of the domain (http://www.example.com) or the non-www version of the domain (http://example.com). "

This could help out a domain's ranking within Google by quite a bit. I highly recommend setting your preferred domain from with Google's Webmaster Tools. Every little bit helps...

Link:
http://.../setting-preferred-domain.html