From Tuna Kumkale:
Domain Informer is a user-friendly tool that checks whois information of a given domain name, making it possible to query any domain name directly from your desktop. It simply informs you whether the given domain name is available or not. If the domain name is not available, then it shows you the complete whois information including registar, registrant as well as the creation and expire dates. Domain Informer has the ability to check 38 domain names in which one of them is the new .mobi domain name.