So you've purchased a ton of domains to park
on your main account, but you don't want Google to penalize you for
having duplicate content. And you know that you could go through your
.htaccess file creating redirects for each and every one of the
domains you're parking.
As your .htaccess file grows and grows,
you find yourself asking, "Isn't there an easier way?" Rockethost
says SURE! Instead of the lines and lines of .htaccess redirects you
could be using, how about these three?
RewriteCond %{HTTP_HOST} !^www.YourDesiredDomain.com [NC]
RewriteRule ^(.*)$ http://www.YourDesiredDomain.com/$1 [R=301,L]
What this means in english:
If someone requests a page, and the domain is NOT my preferred domain
Redirect the user to my preferred domain, including the www I've specified here, please, and tell the browser the content should always point here.
So long as you want EVERYTHING to point to the main domain, this will work like a charm.