On the Google search results pages, I've seen a new icon. I know that they offer flight tracking, but for certain queries they return flight booking info. Example: (this might not work every time) plymouth, tobago will return a flight from Plymouth, England to Tobago, West Indies. I wish I had a screenshot.

James, do you mean something like this?
http://blogoscoped.com/archive/2005-10-26.html#n30