Google shows a special OneBox when you search for "whois", followed by a domain name: for example, [whois google.com]. The OneBox shows the date when a certain domain was created and date when it will expire. It seems that the only provider of information for this OneBox is Domain Tools.
Google launched a similar feature four years ago, but it was removed really fast because it scraped data from Network Solutions without permission. "Google quietly launched a service allowing visitors to look up data on domain name owners from public databases - collectively known as Whois - run by registrars worldwide. Although largely unpromoted, the service generated enough traffic to surpass Network Solutions' (NSI's) daily Whois use limits, which aim to stop spammers and other undesirables from harvesting information about its customers."
This is not the only direct answer displayed at the top of Google's search results: there are many OneBoxes that show maps, stock quotes, weather information, local time, books, definitions or facts.
{ via Matt Cutts }
Update: after 3 or 4 page views, DomainTools shows this message "You have reached your daily lookup limit as an guest user. Please login or register". Maybe Google should partner with companies that have less restrictions.
