Ok I us a particluar web hosting company.  What I'd like to do is some how see a list of what domains are hosted by that company.

My thinking is, all the domains they host use the same DNS Servers, is there a way to do a public whois query and say show me all the domains that use the DNS server XXX?

Why do I want this information?  I have no idea, I just think it would be cool to see what other sites are hosted by the hosting company I use.