[dns-operations] check if a domain has been registered via DNS

[Peng Yonghua]

Hello,

for domain registration stuff we generally query the info via whois.
But whois is slow.
I wrote a simple module to query the domain via DNS system, more 
exactly, query the domain from its parent nameservers.
for example, given yahoo.com, I check the domain name from com's 
nameservers.
if rcode is NXDOMAIN then domain not taken. if rcode is NOERROR then 
domain has taken.

I found the querying is much faster than whois.  module URL:
http://search.cpan.org/~pyh/Net-Domain-Registration-Check-0.02/lib/Net/Domain/Registration/Check.pm

How do you think of it? thanks.