mod_rewrite virtual hosting question...

[jon]

I'm totally confused when it comes to mod_rewrite, but here's what I'm 
trying to do -- redirect any instance of a given domain to a specific 
folder.

So.... let's say I want to visit example.com/index.php, the request 
should go to /var/www/sites/example.com/index.php

What I'm looking for is something flexible -- I don't want to have to 
add vhosts everytime we add a domain to the server, just a site.com 
folder in /var/www/sites

Can anyone help... or point the way to good resources?

Thanks....

	-- jon