To get WHOIS information via PHP just use sockets from PHP. use fsockopen() to open the connect and use it like any other resource stream. Use the port 43 and just sent the domain name/IP address you want to query...but thinking about this a WHOIS query returns only info about registered domains.

I know you can get information about the user from the IP address, gimmie a while and i'll find out what i was talking about....