Protip: For all US-based carriers - If your flight is cancelled or delayed more than two hours for any reason, your are entitled to a refund but you have to ASK for it as airlines will usually offer you a credit first. Be careful though as the refund will go back to the Original Form of Payment, which if you went through a travel agency could be their card or electronic check, so if you booked through a TA like Priceline, Expedia etc go to them first and request the refund. They will try to push you off onto the airline but what happens far too often is the airline will see the ticket as refunded and consider the matter closed, and good luck getting your money back from the TA at that point.

Also: Airlines are only required to offer you any sort of compensation like hotels, food vouchers etc if it was their fault they canceled, ie mechanical issues, crew exceeded Federal mandated hours etc, but if the flight canceled due to weather or something like traffic delays (happens in large airports like JFK, ORD, LAX etc) then that is considered out of their hands and no compensation other than getting rebooked on next available flight or full refund are offered.

Finally: anyone who purchases a Restricted Fare (economy basic, saver fare etc) or spends 400 bucks or more/is traveling with a family or overseas and DOESN'T get trip insurance with trip interruption coverage in this day and age are just stupid. Go through you home/medical/car insurance company instead of the airline directly and you'll get a better deal, usually 25-30 bucks/person depending on the price of your ticket/destination. It will cover not only the cost of hotels, food, clothes and personal items but the purchase of new tickets on another airline if what the company you booked through doesn't have better options available. Ask all those poor souls who spent Christmas stranded by Southwest feel about having to spend thousands out of pocket just to get home. Seriously it's worth every penny.