This script, PHP Whois Lookup, can be used to find a domain owner's contact information, domain created date and expire date, domain name servers, and usually a hint to which service (hosting) provider the might be using.
Demo/Info
http://www.scottconnell.com/php/whois_lookup.htm
Download
http://www.ziddu.com/download/14711813/whois_lookup.zip.html