I've got the multisite functionality set up and working fine (as far as I know). My first blog is working fine in my root domain (dubiosity.net).
I tried to set up the wildcard thing in my DNS settings, but apparently GoDaddy doesn't allow that. So I added an entry for "testsite" (testsite.dubiosity.net) and that's pointing to "@" (my server's address, as far as I know).
But, that doesn't work. I got a Forbidden error.
I guess what I'm wondering is, can I still make this work without the ability to use wildcards? Or should I switch to subfolders? I barely understand what I'm doing, by the way.