I think the only tool that exists to do what you want is FlyerTalk! Everything else has some type of time lag that is similar to the aforementioned site. Smarterliving.com, bestfares.com, travelzoo.com, etc. have some delay because they are, at best, compiled several times a day. I suppose the best way to locate emerging city to city low fares would be the travelocity, expedia and orbitz fare alerts when the fare goes below a certain price you establish but that of course only helps with city pairs you designate and still has some delay. Thankfully, we have lots of FT colleagues who keep us posted on the magical fares but woe to those who do not check FT frequently. Seems like every time I get lazy and don't check FT it turns out that I've missed an MR opportunity. Eternal vigilance may be our only option.