If you are interested in Southwest, you can download the "DING", which alerts you when special fares come up from your pre-chosen city/ies you want to fly out of for your trip. Southwest does credit you the difference if flight goes down and you rebook it. Many people will book 1 leg at a time, so if 1st flight goes down, can use credit toward 2nd, or if you know you'll be using SW again w/i a yr.(I think this is when it expires) you can book RT.
I also use airfarewatchdog.com. Here you can program in which airports you want to fly out of, as well as to/froms you are planning, like Detroit to Orlando. It will send you a daily email w/prices on flights out of the airports you chose to many cities, and then alerts when a good fare comes up for the specific combo you're looking for, and you can click for details(dates available, fly Tues/Thur, etc.) They also post changes in bag fees, security rules, etc., and have even compiled a bag fee chart so you can check to see what you'd pay.
If you're looking for discount tickets, try Undercovertourist.com(great prices, tax & shipping included) and Mousesavers.com. (sign up for newsletter)who will let you know when prices will go up for next yr. & other hot deals alerts, as well as rental cars, etc. Ticket prices have been going up 1st week in Aug., so if you have the funds, buy in July(they have a great refund policy as well, if plans change. HTH!
cassie58
11/08-ASMo & Timeshare
8/09-CSR