In the words of Michael Palin: "It's dead."

MHD was short for Mexican Hat Dance, a remarkable way to travel from Canada to elsewhere in Canada and the US, via Mexico. The benefits were savings on the order of 80-90%, travel in business class on a completely unrestricted ticket, and pick up tons of miles.

A sample itinerary, perhaps the ultimate itinerary, was YOW-YYZ-YWG-YEG-YYC-YVR-LAX-MEX-CUN-MEX-LAX-YVR-YYC-YEG-YWG-YYZ-YOW, in business class the entire way, for under $1400CAD, with stops allowed in any or all of the above cities, and then some, if you so desired. During the recent AC "Fly'N'Qualify" promotion, you could pick up over 25,000 status qualifying miles.

Sadly, it took on a life of it's own, and on May 16th, 2001, UA, MX, and AC killed it. Killed it dead. They took coordinated action to eliminate stopovers in Canada, and severly restricted them in the US. An itinerary that might have cost $1200-$1400 as an MHD now costs $8000-$9000 or more.

If you want to learn more about it, check out this Summary of MHD posts. It contains the entire history, interesting and amusing as it is, up until May 16th when I stopped updating the summary. Be warned though -- it would probably take 24+ hours to read it all. But much of it is an enjoyable read.