Theres an excellent small program that you install on your computer and it makes the whois searches from the program itself. I tried it and it worked well. Unfortunately I cant remember the name, but go to
www.cnet.com and search the software section for "whois" and I think it will show up there, you might have to look for it tho...
Other than that you can do a google search of "whois" and you get pretty good sites that you can use.