http://www.sleepinginairports.net/tips.htm has tips for sleeping in airports. I'll throw in my own thoughts.

• This doesn't really apply to the business-class or first-class lounges. If you can get in there you can eat, drink, and shower at your leisure.
• Sleeping at major US airports is just a matter of finding the space. I think you'll only have to worry about being kicked out at smaller airports that don't have flights coming and going all night.
• If the stores and restaurants are closing, your terminal may be closing for the night. Hide out if you plan to stay.
• A major delay will cause major problems. My longest delay was 12 hours, mostly at Dallas, when DFW closed for heavy fog. The airport was only closed for a few hours, but the schedule fell completely apart.
• With hundreds or thousands looking for space you have to hold onto that quiet corner like a cat with a corn cob.
• On a delay of a few hours on an inner-China flight they gave out pre-packaged bowls of dry noodles. They have hot-water fountains in Asia (almost) like we have cold-water fountains in the US.
• When I traveled with a carry-on garment bag I found it was pretty comfortable when I sat in the floor and leaned it against the wall. Also secure.
• I always have the ear plugs and eye mask, but I don't have room for an air mattress. Maybe if I spent more time in less-developed areas.
• Power outlets make the most valuable real estate. It's worth walking to an empty terminal if you can find a comfortable spot with power. Obviously this matters only if you have a laptop and/or cell phone to recharge.
• Cell-phone modems are cheaper than airport wifi.
• If I am getting stressed I'll schedule a flight with a five hour layover just to give myself some time to decompress.

Links http://www.sleepinginairports.net/tips.htm

I went to Rockford, Illinois for a couple of days last week, and ended up staying the whole week when the snow storm hit. When the lights started flickering I immediately went to Wal-Mart and bought some food and water, just in case, but everything worked out.

Here's a picture I took while driving across Indiana. It is just as cold and windy as it looks.