Do you often fly oversees?
I search for my plane ticket a lot to buy most economical one.
How to buy cheap ticket ?
I found many times Tuesdays, Wednesday and Thursdays cheaper tickets
I look at these websites often for good airfare deals;
usdtravel.com
If you are member of military, this website offers discount tickets
cheapoair.com
LowFares.com
travelzoo.com
Expedia.com
wholesale-flights.com
tripmama.com
priceline.com
bookingbuddy.com
cheapflights.com
mobissimo.com
I also look at airline websites such as;
lufthansa.com
( too bad Lufthansa canceled direct flight to Frankfurt, from Portland Oregon. That was the shortest flight between Frankfurt Germany to Portland, OR, USA, even though Frankfurt airport is a nightmare )
delta.com
(they have the most friendly stewards, just avoid flying from JFK, there are too many delays)
klm.com
( I love Amsterdam Airport Schiphol, to me it is the best comfortable airport )
united.com
continental.com
aa.com
Just keep in mind, if you get an American Express credit card, you can earn miles or save money when you travel.