Thanks for all the information regarding fare searching sites. The Dream Map is what I was thinking of originally, but we have a good collection of sites in this thread so far.

Still, it would be nice if you could just get a list from any airport sorted by price of the least expensive fares, regardless of the destination. Perhaps such an ideal tool would let you filter by airline, fare, type, etc. It seems the presently available sites don't necesarily sort by lowest fare out of your city. But who would use such a site....besides people on mileage/segment runs? Hey, maybe mileagerun.com. You could have automated email agents that notify the customer when fares meeting certain requirements are met. Say fares for less than $200 out of BOS, for cities with a distance from BOS of 2,500 miles or greater. Personally, I'd gladly pay some subscription rate to have a really sophisticated travel tool that is more like a travel agency CRS and less like a consumer friendly site.