Yuck. Not a good situation. I also think it's ridiculous that they couldn't seem to find a way to get those people off the plane and back to the airport for a delay like that. 7 hours? I once was stuck in a plane sitting on the tarmac for three hours in Toronto because of thunderstorms, and that was no fun, despite having a water bottle and some trail mix with me as well as books and headphones to entertain myself. Thankfully it was not a full flight, so nobody was sitting next to me and there were no screaming babies or obnoxious passengers, or the situation would have been far less tolerable. The suggestion someone had about earplugs is not a bad idea, although I am always uncomfortable wearing them in situations where a bunch of random strangers are around and I'm not traveling with anyone I know. At least with headphones one can still hear their surroundings if necessary.