I just found this thread, it has great tips. Many of which I have used myself in previous situations.
A few years ago DH and I were in the air, on the way from Vancouver to Toronto, when all the tv channels (satellite tv on West Jet) suddenly cut to a plane that had gone off the runway at Toronto. The airport was shut down for an indeterminate amount of time.... Our flight ended up being diverted to Winnipeg, and all West Jet told us was to either stand in line or call their 1-800 number to see about getting rebooked. DH and I took one look at the amount of people coming in (lots of planes getting diverted there) and decided that I would use my cell to call the airline, while he went to the big hotel advertisement board and used the phone to look for a hotel room. The hotel manager even gave us 15% off after DH told him why we were booking a room at the last minute.
Turns out we had to wait 3 days for another flight home, but it turned into a Winnipeg mini-vacation for us. When we got to the hotel and watched the news that night we saw tons of people stranded in airports all over the country, sleeping in the terminal because they had no where else to go. We were so glad we'd found a room, because our hotel booked up quite fast due to the number of delayed people in the area.
After that experience we know you have to be flexible, avoid standing in line at the counter to make changes if you can do it on the phone, and make the most out of travel delays. We explored the city, did some tourist stuff and just relaxed, knowing our situation was 100% better than many other stranded people!