Hi,
I need to know if there are free or low-cost webservice(WSDL)
available out there that answers whether a domain name is available or not.

Dear Top Carrot, 

"Whois.net" is only one of the many services where you can learn more
about available domain names.


If you type in a certain term at the "Whois Lookup" rubric, you'd get
the registration details of registered sites.

For example, if I type "Google" into that box, I get this page: 
http://www.whois.net/whois_new.cgi?d=google&tld=com 

Which tells me to go to: http://www.internic.net and get the full
details there. Which is:
http://reports.internic.net/cgi/whois?whois_nic=google.com&type=domain

And you can also get a full report here: 
http://dndetails.com/www.google.com 

But you can also preform a search on the Whois.net, with a keyword, to
see if there is such a site registered. For example, if I go to the
second rubric ("search domain by keyword") and enter politicalguru -
two sites are trying to steal my good name!

Next, you have an option to find available names; and you can also see
what past domains are now free.

I hope this answers your question. Please contact me if you need any
clarification on this answer before you rate it.

I find 1&1 good. They have a US(.com) and a UK(.co.uk) site.

There's talk lately that domain name searches are being looked up and
being registered soon after if they're not taken for whatever reason.
Unfortunately this is causing many people to lose confidence in using
those availability searches.

Assuming we're talking about .com, there is one site all domain
registration companies query: the Verisign COM NET Registry:

http://registrar.verisign-grs.com/whois

They query directly to the Registry. No domain registrars can lookup
one another unless they have some sort of agreement.

Goto www.networksolutions.com this site will let you know if the
domain is available and by what top-level domain is is available with.