I’m asked with some regularity, “Could you let me know when the fare from X City to Y City is really cheap?”

And to some extent I keep on the lookout, but mostly I just hear (via e-mail, via my own checking, via Flyertalk.com, or via ScottC’s email list) about especially good fares.. but not tied to specific destinations. So I usually say “sure, if I see something I’ll let you know. But why don’t you let the internet travel agencies do it for you? They will, of course, since they want to sell you a ticket.”

And I suggest the following:

• Orbitz: http://www.orbitz.com/dealdetector/
  
• Travelocity: Choose “FareWatcher”
  

• Expedia: http://www.expedia.com/daily/promos/promomail/default.asp?rfrr=-1265

Now, if what you’re trying to do is just find out where you can fly cheap from where you are rather than looking for specific destinations, you should use:

• Travelocity’s Dream Maps

• Digital City’s Daily Deals (This link is for Washington, DC but major cities have their own links.)