The airline industry is profitable again, thanks in no small part to the billions of dollars in fees it collects from passengers every year. And it’s not just reservation change fees ($2.3 billion), checked baggage ($2.7 billion) and “miscellaneous” fees (almost $3 billion) that air travelers shelled out in 2009; now carriers are getting even more creative with their charges, imposing them for everything from redeeming frequent flier miles to carrying a bag on the plane.