Unfortunately there isn't too much one can do.

I always bring my mp3-player, so I don't have to listen to everyone yapping on their cellphones. Most people at the airport are somehow cellphone addicted. They call their families constantly to tell them that they are still in the terminal. Terrible.

Most of the time I just pick up an interesting magazine at the airports store.

I don't like to read a book in the terminal, since I always get distracted from a story if I don't have a quiet place.

Sometimes I have my laptop and I do something with it, but mostly I prefer not to. I usually find the WiFi hotspots (wireless internet) too expensive to use anyways.

I have been thinking about getting a PSP (Play Station Portable), but I think I would get bored with it very quickly.

I have a Compaq IPAQ (PDA). You can download an emulator for old Lucasarts Computer games (like Monkey Island, Maniac Mansion ...). You still need to have the original games, but they can be bought really cheap these days. I can also upload E-Books and read them. I have played these PC adventures for a while but I got bored of that too.

These days I just watch people and if I have a very long layover I just get a magazine. If I am going somewhere (not coming back), I usually have a travel guide of the place I am going to that I haven't read cover to cover yet, so I am using the time to plan my trip. For me it is important to figure out the best places for photography.

Not a lot of new ideas I guess.

Andre

Travel Photography 

Although it does depend on how long the lay over is. But I like to browse through the terminal's gift shops. If it was a longer delay some airpots have hair salons and you might like to visit there. These are just a bit different than the normal reading or listening to music ideas but could be of use.

If you have a lot of time, I recommend to get some transportation into the city and do some sightseeing. You would be surprised how time flies then.

Andre 

I agree with Andre. It is not oftentimes that we are in another place and I would love to roam around and get familiar with it before I go and having an extra time to do that would be very great and nice. :)

I don't think I could bring myself to actually leave the airport.  I'd spend the whole time in a panic that I would miss my flight.  I could never enjoy myself.

Just plan enough time and if you loose the flight due to a very long security line (can always happen these days), you should be able to get your ticket replaced for the next flight. Just make sure you make yourself look bigger than life and hard to deal with when talking to the airline reps .

Andre

Travel Photos

I really do not think that I would leave the airport. I always bring a good book with me, so I can read while waiting. It makes the time pass faster.

I just bought a new PDA (high res VGA screen, 625 MHz Processor). It should be good enough for games, reading books, music, movies and a lot of other things (going through photos or surfing the internet if I find a wifi spot).

Usually I am busy trying to keep up with everything that happens around me. Somehow I cannot concentrate on anything in this kind of environment (too loud, too much happening ...) 

Andre

Travel Photos 

I'm afraid, I don't have any other ideas either. I usually read a book or watch the people go by. If there is enough time and the airport has some good restaurants, we usually go and get something to eat. I also just like to hang out at the bookstores. I don't have enough time to do that at home as often as I'd like to, so I use the time at the airport to peruse new releases and often end up buying a book or two. If you bring your laptop, you could also watch a movie.

Boring nights in a hotel? That rarely happens to us. Either we don't get in until late at night, in which case we just drop into bed and sleep. Or if we do check in earlier, we usually leave again to explore the area. If we are in a city, we stake out good spots for night shots/skylines and go out for dinner or explore the nightlife. On the rare occasion that there really is nothing to do, we usually plan the next day.

I usually have a layover at the end of a really long flight, and I've been known to curl up on the floor with my head on my pack, and sleep. 

On the way out I've usually got something that I forgot to do and I spend my time making phone calls or even paying bills.  I once gave a stack of bills, all ready to go, to the security guard in San Francisco and asked her to mail them.  She did.  Now I'd probably have Homeland Security all over me.

I always have two or three books with me.  I start my journal, you know, "Well, I'm finally on my way..."  I eat.  The last time I left I had tons of rollover minutes left on my cell phone, so I called everyone I knew.  I take walks.  I've gotten in an hour or so of exercise in many airports.  I sometimes take a crossword puzzle book.

Count me in as one of those who just cannot leave the airport.  I am a stickler for being EARLY.  My biggest fear is missing a flight and it being *my* fault.  I love to bring little handheld games like yahtzee and solitaire.   I also use the time to eat. :)  I love to find Cinnabon or some other yummy treat.   I buy really trashy magazines, also (ones I would normally never read)   I try to make the best out of any time spent waiting.

Woahhhhh, you are one of THOOOSE who always get on my nerves by finding the chair right next to me and yapping on the phone so loud that all my peace is gone while they have to tell the person on the other line all the meaningless stuff (what the weather is like, whats on the screens, and what they had for lunch).

Sometimes I am close to taking one of these damn cellphones and crushing it.

LOL. Next time I will look for someone like that, find a place next to them and start calling people for no apparent reason to yell at them so they will have to hold their phones at arms length from their ears.

No seriously you know I am just kidding, right?

And there I was wondering who buys this stuff and even worse eats it

Seriously, thats about as bad as it gets foodwise. But I appreciate if the person eats their stuff at the airport and not in the seat next to me on the plane.

More then once I found someone eating pizza or even worse home cooked garlic with some food in it in the seat next to me stinking up the entire airplane. In that case I wish it would have been just a Cinnabon.

Personally I think I would get a sugar shock from those and start tweaking.

Isn't it nice if they have one of those LCD Televisions at the airport running CNN all day? I'd rather watch TV then people going about their nasty habits. 

I myself always carry a good book on me when traveling just in case of this exact situation. Also there are alot handheld games that you could buy some of the systems even play movies nowadays.

Most airports these days, especially in the big cities, have as many stores as shopping malls. I use long layovers to do some window shopping. Also if there's a game I'm interested in, I'll go into a sports bar, grab a hamburger and a couple of beers, and root for my team (which practically guarantees they'll lose, but oh, well!) Besides that, I like books and word puzzles. Sometimes I'll bring my notebook along and work on writing projects, stuff like that.

I always keep an eye on my flight time, though. My parents were once told that their flight would be delayed by four hours, so they left the airport and went to a movie. When they got back, they learned that the problem had been fixed and the plane had departed more or less on time. They were NOT happy travelers.