Website: The ITA Software Matrix

I would like to share a tool I use to find the best deal on airfare. I found this site one of the easiest and most flexible to use. It searches nearly all of the airlines to find the lowest fare between destinations. It is also very fast!

http://matrix.itasoftware.com

It is free to use for anyone. Simply click "Log in as guest" and you can begin searching. When booking vacation I like to use the Full Month search or Weekend search so I can see which days are cheapest. It even mixes airlines to get the best price. Very handy!

You can also specify a certain airline or airline alliance so you can get points for your particular program. I am currently an elite member of Delta Skymiles so I focus on Skyteam airlines, for example. The fare has to be a lot lower than a Skyteam member for me to buyoutside of it. Elite status has many benefits that I value as a business and leisure traveler.

I should note that you cannot book the flights from this site. It is a search only tool meant for travel agents. Once you find the fare you want you have to go to the airline's website and book it from there. It is a lot less of a hassle than it sounds like. Just jot down the times and flight numbers and make sure it matches up when you book it.

They are also working on a new version, matrix2, which is supposed to be even better. I look forward to seeing what new features they add to the already great tool. They provide links where you can have a look for yourself. So far I have only seen layout changes but have not used it enough to make a complete evaluation.