Google’s New Flight Search

Google Experiments With New Flight Explorer Feature, Matt McGee, Search Engine Land (Dec 12)

Google’s new Flight Explorer helps you find best price over several days, and then book through the airline.

Google Flight Search Toronto to London UK

“Flight Explorer auto-detects your location and presents several destinations with a price chart showing the range of airfares available over the next two months”

There is a very detailed help page to explain the options.