Just saw another feature on Google search results page. I searched for LonelyPlanet and the first result which usually gives bunch of options related to a result, now shows another option: search that site from results page directly. I repeated the experiment with National Geographic and Discovery Channel and got the search box, but it didn't appear for BBC, Rediff, Hindustan Times, TCS, Animal Planet and Al Jazeera. Is it only for travel and wildlife sites?