Well I'd say its more of a DNS thing than a server config thing. However server config is the solution I went with. I made a 'default' virtual host that matches no domain names. Put a little note and thumbnails to all the sites hosted on the server. Threw up a robots.txt that blogs everything. Now if you type a non-existent subdomain, or my server's IP, you'll get this page instead of one of the other domains. I should get more IPs from my colocator. This is way off topic but is google thought to give your site a better ranking if your domain's ip points back to the same site as the domain?