I've never run into a socket in a hotel room that was loose enough to cause problems for me, but if I ever do, this thread has given me the solution. I figure all I'll have to do is show it to the hotel staff and say, "So, I would never do such a thing, but there are people out there who are crazy enough to wrap tinfoil around plugs and stick them in loose electrical sockets. Although I'm not such a person, the next guy might be, and as a thank you for telling you about this problem, you'll send someone right up to fix it, right?"

Admittedly, this still doesn't solve the plane problems.