I was always weary about taking guitars on planes...when I take my PRS I always have a debate with myself as to wether to tell the guy "hey that guitar cost like 2000 pounds, so be careful" or not...a man who knows the value of my baby, may be tempted by the allure of riches hehe.

I am now comfortable travelling with guitars, even with gigbags (just pack soft clothes inside the gig bag, cushioning the guitar...and always looses your strings a bit.

they usually allow you to carry your guitar on to the plane, then leave it at the front in the fragile hold, or they'll tell you to take it to a certain desk at the airport terminal, where they will take it the fragile hold themselves (this is usually in the passenger section of the plane, not the cargo hold, so you dont have to worry about air pressure or cold temperatures).