im not sure of the legalities of it all but i cant see that there would be any problems! im sure you can book your flights through different american sites on the internet yourself. i have never done it but have looked at a few sites and thought about doing it as like you say it is cheaper. maybe your friends in the states could talk to a local travel agent over there and see if they can help, or maybe one here would be able to help. let me know how you get on, it is an interesting question and one i would like to know the answer to for future reference. good luck