I can't do it and don't want to. It takes me out of the experience. I cannot imagine per say listening to anything BUT Grim Grinning Ghosts on Mansion. If I did play my own music, then Space mountain might as well be just another coaster.
I shake my head each time when i see it at dispatch when I am at Space. it CAN be a safety issue as I have seen a few times guys and girls getting their cords tangled in a safety restraint.
...As I see it