Yes, on Travelocity , you can check the box saying Search all dates for best fares. Then you get the fares for each airline; when you select one, you get a calendar showing

when the fare is available. For North American travel, lets you check a box saying Flexible dates

and get various types of flexibility: a weekend in March, or a trip of 7-10 days in March, for example. If it's a route that Southwest

flies, their fares don't show on these sites, but on you can select their Shortcut to Low

Fares.

Andrew Missouri