The opportunity to fly cheaply as a courier is fast going extinct.  In the past, when companies had to ship important documents on short notice it was often cheaper to pay for a flight than to give it to UPS.  Today those documents are emailed or faxed and the courier flights are rare birds, indeed.  There are still organizations out there trying to make a buck off of hopeful travelers and even a few lucky travelers who score a cheap or free flight in exchange for their baggage allowance and some flexibility.  Nora Dunn outlines how to try your luck.  Via Vagabondish.