We borrowed a portable dvd player for the trip; we are now considering purchasing one.
DS used it driving to the airport, on the plane, and in the hotel room! The tv's at POP have av jacks, so we just plugged it in and watched dvd's on the big screen.
This worked out nicely because ds watches very little television, but he does have a few favorite videos that are familiar. so when we returned to the room, and he needed some down time, it was great to just pop in his familiar video and snuggle on the bed.
just wanted to let you know that they can be used this way - I never would have thought about it but dh is right on top of everything electronical!