Yahoo! Farechase is an online price aggregator tool that runs your desired flight or hotel bookings through about 25 different websites and comes back to you with the lowest available airfares.

It was pointed out to me that they do not run Southwest Airlines' fares... so it may pay in some situations to check out their fares directly, but I was impressed with the speed and actual results i saw on a difficult item to find reasonably prices.... Austin to Denver which I found for $178 round trip. A reasonable price from what my research has been. It also found a round triip Austin to Vegas for $129 which I'm told was very reasonable.

Alll in all, I'd give it a 8 out of 10 on the makes life easier scale as I know what a pain it is to search through the many available flight search tools on the internet. The neat thing is that thanks to the Yahoo! API you can give it a try right here. Let me know what you think.