Some airlines don't show up in the airfare search results. Is there a search site that includes ALL airlines?
Southwest, for example, sells online only through their own web site and their airfare results will not show up in the popular search engines results (like expedia, etc.). It would be very convenient to have a web site that searches these web sites and brings up the results. Then you go directly to the airline web site and book your flight. There are a lot of airlines like Southwest that don't participate with the big search engines such as Travelocity and expedia.