You may have learned already to reconfigure your WP3 so that it loads in MU mode, and set it for subdomains.
Evidently my Dallas client claims that instead of just subdomains, there are some tricks you can do (cpanel? wp-admin? plugin? config file change?) to make a full domain like example.com for a subdomain, instead of having a subdomain like blog1.example.com.
Is this true? How is it achieved? Does it have any caveats that you can think of?