Prior to the spring of 2009, U.S. passport holders traveling on Ryanair flights were obliged to use the airline check-in desks. This policy has since changed, and now U.S. citizens can avail themselves of the option to check in online. Should you decide to exercise this option, be sure to print out your boarding pass prior to heading to the airport. A hefty fee awaits those who show up without the print-outs. (In all my experiences to date, when flying round trip, I was able to print out boarding passes for both outbound and homeward journeys at the same time.)