WordPress MU

Ok so I have installed wordpress MU on my server and it is working. however I am wondering about the * wildcard DNS for virtual hosts. Is this possiable and if so what do I need to do to make sure it is working. I would like to have the users blogs at xxx.domain.com where xxx is the name they choose

as i understand it, you will need a unique ip for your domain, and then add a wildcard dns. I have setup such a thing at http://isthy.name

msg me if you need more info.