Am I overstating it? Perhaps. But then again, no. That luggage we drop off at the curb might as well be loaded with wads of cash. (There's gold in them thar bags!) According to the Department of Transportation, airlines collected a cool $7.8 billion in "ancillary" fees in 2009, the largest share coming from checked baggage fees. Other sources included pet fees, reservation change fees and more. Still, I continue to wonder why - and how long - will Southwest be left out of the gold strike?