Dream Maps address the question, "where can I go if I only have $XXX to spend?"
http://dps1.travelocity.com/dreamMap...p_arp_name=sea

The map will show up to 18 "popular" destinations whose lowest roundtrip airfares (exclusive of government-imposed taxes and fees) do not exceed the specified price ceiling, which defaults to $300.

Note that Dream Maps are not updated every time fares change, but you will see current fare information whenever you query a particular city-pair.