The www Problem

IUsability.com:

When visitors type in your site’s URL, they have many different options. Do they add the http://? Do they add the www? Do they leave it out? Do they mistype the URL somehow? There’s a lot of variety when it comes to a visitor trying to get to your site and it improves usability when you eliminate as much as possible. Shouldn’t the www be meaningless by now?

Also see this.