I know that whois.sc has a lot of DNS issues as GG mentioned - but the format for finding out about one specific domain would be
http://whois.sc/domainname.com doesn't matter if you use the
www.whois or without
In the page they return is a link for a reverse lookup, it will also list the nameservers, the "supposed" registrants name and contact info and lots of other nifty stuff like what other domains are also on that IP address