Sounds exciting? The bad news is that the service will initially be limited to US cities and will only display round-trip economy flights - though the system is online now and can be accessed at google.com/flights. Nonetheless, we can see how this relevant this service can be, especially since it is integrated into a search engine that everyone uses.
More details including a video tutorial below:
Techspot - Google Flight Search features four main characteristics that the company hopes will lure you to their service. These include fast search results, a simple list of the most relevant flights, seeing which travel dates are the least expensive and exploring alternate destinations.