Half-an-hour - The amount of time in which we theoretically could have caught the 6-something flight to London, the one after the one we were originally scheduled on. The lovely gate assistant was halfway through giving us seats on the flight when her supervisor insisted she close the gate. We were willing to wait - it gave us time for dinner.
Two-and-a-half hours - The time spent in the choppy belt of storms and wind over the Great Lakes and Canada. ("We'll clear this in half an hour." "It's been half an hour and it's gotten worse. Don't worry, we'll go higher soon and it'll be smoother." "Oh look, we're higher now, and it's even more choppy up here." And so on.)
Ten minutes - The time spent waiting in the really slow missing luggage bag to file a claim for our third bag before I got bored and wandered off to look at more of the many stray piles of luggage lying around the terminal. Our duffel, it turns out, had been enterprising and caught the previous flight.
Two hours - The time it took to get from Heathrow to Temple, where the District line, already laboring under severe delays, shut down entirely for repairs. We gave up and took a taxi.