At 10:15 pm I discovered that I had not brought a Macbook power supply on the trip. I was in a hotel on Coronado Island, and early the next morning I was flying to an aircraft carrier off San Diego for an overnight visit. I doubted that the carrier had Macbook power supplies laying around, so I was in trouble. I posted a message to Twitter that I was in this predicament, and within ten minutes, five people offered to bring me a power supply. I took one of them up on the offer, and he delivered it to me within an hour.