The wife and I took a flight from ORD to PHX on a USAir (AWA) flight in January 2007. It was -3F at ORD when we arrived 2 hours before scheduled departure, but I figured we would be late taking off due to the snow and de-icing going on. It didn't bother us as I was watching everything and listening to it all on the scanner the whole time, and the wife has endless patience when she has knitting to do.
We boarded about 20 mins after the scheduled departure (about 1300 IIRC) and pushed back for deicing. We were one of the lucky ones, as the truck pulled up right away. I had heard some planes waiting over 2 hours for deicing, we were done right away. We took off almost exactly an hour late, but a lot earlier than I thought we would.
Being the geek that I am, I brought my laptop and little GPS receiver. I found a sweet spot were I could put the GPS receiver by the window unobtrusively and watched our departure from ORD after they turned off the seat belt sign. StreetAtlas USA reported a cruise speed of about 525 MPH, give or take a few for the first hour. I noticed the cabin crew had been congregating in the rear of the plane and saw that a passenger had taken ill. A few mins later I heard the Capetian ask for a doctor on the PA. On the scanner I then heard him talking to "Amarillo" on an Arinc channel (I presume) and informed them of the situation and asked advice. The captain advised that he was going to declare a medical emergency and they suggested Kansas City as the best location for the passenger care.
The Captain then got on the radio with the Center and immediatly banked hard and turned due east as we had already passed KC. The speed increased to about 620 MPH during a quick descent. They then informed the pax about the situation and soon we were in KC and EMS was taking care of the sick passenger. After refueling our A320 we took off again and resumed our journey. They did a quick drink and snack service, ran the movie and we landed at PHX about 3 hours late. Before landing the cabin crew check with each row as to find out if they were connecting with other flights and later came back and told them what gates to go to and what time the flights would take off. Since PHX is a hub for the AWA division of USAir most people were able to make connections pretty easily. Since I know sign language I helped a deaf passenger figure out her arrangements, for which the crew was appreciative.
The crew handled the situation well, keeping the rest of the pax informed while retaining the dignity and privacy of the sick passenger. I knew the nature since I heard the captain talking on the scanner, and it was handled very well and discretely. They made sure that everyone got to where they were going and that luggage was transferred to the new flights.
The way the flight and cabin crews handled the situation rubbed off on the pax. Not one groan was heard or complaint made by any of the packed flight's passengers.
Having heard horror stories recently I was prepared for the worst, but even with all the problems thrown at this flight everyone came off the aircraft in a good mood, well except for one lady left at KC...
BTW, the cabin crew on the way back to ORD a week later got a kick out of watching our progress on my laptop. Several times they stopped by to check on our progress, at least until the battery died on the computer.