Personally, I redirect www.example.com to example.com (example.com is already a web site, no need for redundancy and it makes hard then for people to assimilate blog.example.com (so, a blog is not a web site then?) or newyork.example.com (where’s www?) but I digress). I redirect at the Apache level doing:
<VirtualHost *:80>
ServerName www.example.com
ServerAlias example.org www.example.org
Redirect / http://example.com/
The trailing slash in “Redirect / http://example.com/” is important 