I'm not quite sure what you mean (though I'm not arguing). I set up my own DNS manually.
Create a rackspace cloud server, grab that IP and use it in an A record on name.com.
Create a rackspace cloud server, grab that IP and use it in an A record on name.com.
So, say you have valid records for .yourdomain.com and www.yourdomain.com. Those two hosts will resolve as you would expect them, but *.yourdomain.com will resolve to a spam page.
Thanks for the tip on setting up DNS. If I create a rackspace cloud server, I imagine there is something special I have to do to make it a DNS server, right? Does it just work straight out of the box?