To WWW or Not That Is Google’s Question?
The Plugin That Lets You Have Your Own Way With Google..
If, like I have a couple of times, you have forgotten to check the URL of your WordPress site when you first set it up, click on Settings, the first screen that comes up will have the WordPress Address URL and the Blog Address URL.
For setting up as better Search Engine fodder they should both be:-
http://www. then the domain name. If your site addresses are just the http:// then you are in need of this plugin. It is called Enforce WWW Preference. You can find it here:- Enforce WWW Preferences
Once again, if you have upgraded to the 2.7.1 version of WordPress then all

Smashy download
you need to do is, download the zip file, go to Add New in the Plugins section of your Dashboard menu, browse to where you saved the zip file, click on the Upload button, when the next screen comes up, click on the Activate plugin and you’re nearly done.
One last step, you need to go to Google Webmaster Tools, your Google account gets you in (don’t have a Google account?, sign up for one it’s free).
You need to verify your site by adding a piece of code that is supplied.. This piece of code goes into the header.php file in the Editor Section of Appearance on your site. Look for these tags </head> <body> and paste the code before the </head> tag, click update/save.
Now go back to Google Webmaster Tools and hit the Verify button and all should be well, your site should be verified.
Now in the Webmaster Tools, click on Settings in the side menu and you will see the preferred domain feature options for whichever way you want your URL to be indexed, the www or the non www.
This plugin will help preserve your permalinks by enforcing your no-www or yes-www preference (http://example.com/ vs. http://www.example.com/) and will strip off index.php from the ends of URIs.
Google Webmaster Tools is not a bad place to visit, they have lots of good ‘stuff’ there to help with your sites, have a wander while you’re there doing this.
There you go, some talented person has coded this for you and me, to help us keep the search engines happy and coming back to visit our sites.
If you find the plugin useful, then why not let the person who built it know. If you aren’t comfortable with the Paypal button, Mark has a great wish list with Amazon. Just thought I would mention that as the wish list is a good idea. Go push his buttons, you’ll find them at the bottom of the plugin link here