Has anyone tried running xxx.subdomain.yoursite.com? Confused? Read on..

Wordpress MU is beautiful, simple and clean. Massage it with a little creativity and you can even build a brand with it.

I install my MU's to run the subdirectory option. Subdir's are great but I want to go 1 level deeper and offer categories. Let's use geography as an example for mydomain.com.

1 MU Install: alaska.mydomain.com
Users get xxx.alaska.mydomain.com

1 MU Install: japan.mydomain.com
Users get xxx.japan.mydomain.com

1 MU Install: nyc.mydomain.com
Users get xxx.nyc.mydomain.com

Now my brand has 3 separate installations. What a pain, right? Not really! The user base of each MU install is completely different. The plugins, templates and vibe of each MU install is completely different.

Has anyone tried this hierarchy?

alaska.mydomain.com/xxx is not an option because you want to allow the domain mapping functionality.