Bing has been doing something like this for a little while now (through their acquisition of farecast.) Check it out: http://www.bing.com/travel/flight/flexible

Bing has been doing something like this for a little while now (through their acquisition of farecast.) Check it out: http://www.bing.com/travel/flight/flexibleTravel?dm=07%2F02%2F2010&p=1&tvl_t=graph&form=FORMTRVLGENERIC&o=BOS&e=LAS http://www.bing.com/travel/flight/flexibleTravel?dm=07%2F02%...