Room Trade Site connects travelers who are stuck with nonrefundable hotel rooms they can't use with those looking for last-minute accommodations. The best part: Roomer does all the legwork, verifying reservations, changing the name the reservation is under, and transferring payment to the seller after the buyer checks out. Roomer does not charge a fee, but the company notes that most methods of payment transfer, including PayPal, charge a small fee for transactions.