I didn't notice this before, but I was using Chrome's Omnibar to load up Facebook, and before I finished typing in facebook.com on the RHS a little widget popped up saying "Press Tab to search facebook.com".

So I hit tab and the Omnibar brings up another widget on the LHS that seems to switch the Omnibar to search only the contents of Facebook.
Very useful, as the majority of the time when I'm searching I don't want to search the whole of the Internet, but just the contents of a particular site, for example Wikipedia
Strangely, the Facebook search results doesn't bring up the search dialogue like in the Wikipedia search result, but just a link to search
I did a bit more poking around and discovered that which sites are searchable are stored in the configuration. Just load up options, basics tab, hit manage:
And there's a list of sites which Chrome can search the contents of









