If you're traveling with someone, discuss a central meeting place in case you get separated. My husband and I were in Paris waiting to board the Metro. He was able to board the train, but I was left behind on the platform. Having a plan saved both time and needless anxiety.

Pack a couple of mountaineering carabiners. Clip one through the handle or strap of your bag and secure it to something solid wherever you may be (to a bench in the park or in a train station, to the railing of an overhead compartment on a bus, etc.).The carabiner adds a bit of security, especially if you're snoozing.

Don't rush off the car-rental lot. Before driving away--especially in foreign countries where the controls might be unfamiliar-test the headlights and brakes, and look for the extra tire and changing tools. I once had a rental with malfunctioning brakes in Mexico and caused a minor accident--one that could certainly have been avoided had I checked them properly before leaving the lot.

If the zipper on your luggage or your clothing is giving you any trouble, rubbing some lip balm or candle wax onto the teeth should loosen it.

Most hotels provide cloth shoe mitts but not polish. In a pinch, a dollop of skin cream on a shoe mitt (or even a tissue) can make scuff marks vanish and leave shoes as shiny as if they'd been cleaned by a pro.

Check out worldclimate.com to find monthly average temperatures and rainfall for thousands of cities worldwide. You can avoid countries during their rainy seasons, and the information is useful for figuring out what to pack.

Don't be afraid to go to a foreign pharmacy. I forgot to pack my prescription medication on a recent trip to France. When my problem acted up, I went to a local pharmacy. (Look for the green cross.) The pharmacist provided my medication without a prescription and at a fraction of what it would have cost in the United States. In fact, one could benefit by stocking up abroad on medications that would normally be acquired at home at a much higher price.

The couple of hangers provided on cruise ships aren't enough for weeklong trips. So I save wire hangers from the dry cleaner and slip a few into our suitcases while packing. I then leave them behind for the next passenger.

On the final day of a recent Caribbean vacation, I tried to arrange for a late checkout, but was told it wasn't possible. The hotel offered me the use of a day room; it would have been perfect, but it was being used by other guests, and there was a very long wait for the shower. I went back upstairs and saw that someone was just about to clean my room. I told the housekeeper that I understood she had to do her job, but I wondered if I could I take a quick shower first. She offered to clean next door while I took my shower. I tipped her $10 and then left for the airport.

Scuba-diving vacations can get expensive. As I start planning a trip, I call one of the local PADI dive shops and ask the employees about accommodations nearby. They give me hotel connections I couldn't find on my own, and I often save enough to pay for my dives.

Destinationcoupons.com supplies free discount coupons for cities all over the United States and the world. Print them out on your home computer and save on hotels, shows, rental cars, restaurants, and many other activities.

Take along an extra duffel bag for your laundry. As your vacation progresses, throw dirty clothes into the duffel, keeping your suitcase for fresh clothes. At the end of the trip, put a tag on the bag and check it at the airport. This will also give you space in your luggage to bring home souvenirs or new clothes.

Attach a few carabiners--the kind of clips rock climbers use--to the top of your wheeled suitcase. Purses, cameras, and shopping bags can be clipped to your suitcase, giving your hands and shoulders a rest while you're walking around the airport.

My hearing loss once made it impossible to hear any alarm clock. Then I found the Shake Awake, an alarm clock that vibrates. I no longer stare at the ceiling all night prior to an early flight in fear of oversleeping. I clip Shake Awake to my pillow or place it on a hard surface near my bed, where its rattling definitely gets my attention.

Turn off your fridge's icemaker before you leave home. And remember to empty the ice cube bin. The power was out for several days while I was away recently. When I got back, the melted ice had refrozen throughout the freezer compartment. It took forever to clean up.

When not taking pictures, keep your memory card away from your camera. It's a simple method to ensure that any photographs you've shot will be safe even if your camera is stolen. My husband and I learned this lesson the hard way when we lost 250 shots of Kauai.

If you plan to travel to a less-developed country, pack an extra suitcase with hand-me-downs of all sizes. Housekeepers and other resort workers make so little money that the clothes are greatly appreciated. On your way home, you can use that empty suitcase for souvenirs.

Check fares periodically after booking your airfare. The airline may have a sale, and buying new tickets could save you money, even after you pay the change penalty. My wife and I used Travelocity's Fare Finder to pocket $187 each on a recent trip from Seattle to New York City, simply by re-ticketing.

Don't settle for the first answer to your travel question. If you need flight information, it's a good idea to phone the airline more than once and ask the same question. Recently, I wanted to see if I could fly standby on an earlier flight the same day. The first time I called, I was told that the earlier flight was booked. The second time, however, an agent said there were in fact seats available, and I could certainly fly standby. In the end, not only was I able to get on the flight, but I was upgraded to first class.

By starting a blog for each trip--at blogger.com, among others--you can keep your friends and family up-to-date on your adventures. All you need is an Internet café to add entries and photos while you're on the road.

Using your frequent-flier miles, you might be able to visit two cities on one ticket. For example, my wife and I always trade in our Delta miles when we visit our daughters in Dallas and San Francisco. Because we have to fly through Dallas to get to San Francisco on Delta, we can stop over in Dallas for as long as we want before continuing on to San Francisco—and we use only one frequent-flier ticket each.

I never leave home without dental floss. I've used it as a clothesline between tents in Botswana's Okavango Delta and to replace a lost screw for my sunglasses in Malaysia. I even cut off a piece of floss the size of my waist and headed to the night markets in Bangkok. My "tape measure" assured a perfect fit!

Before my last long flight, I went to librivox.org and chose a bunch of books, short stories, and poems to download to my iPod--for free. The site has both adult and children's books, and the list is growing. All of the titles are in the public domain, and they're read by volunteers, so there's no question of copyright infringement. Even if you don't own an iPod, you can download them to your computer and burn them onto a CD.

Note the expiration dates of any debit or credit cards you plan on using while you're away. In Budapest, I tried to withdraw cash with my ATM card, only to find that it had expired just days before.

Before I embark on a trip, I cover the dirt of my potted plants with plastic bags after watering them well. (Cut a few slits in the bags and keep plants out of direct sunlight.) The soil will stay damp for about three weeks.

My husband packs Q-tips in a plastic cassette case. It's small and snaps shut, keeping the cotton swabs clean and dry.

If your flight is canceled, don't just wait patiently in line to be booked on another flight; call the airline's 800 number. They'll answer your call faster, and you won't be waiting with other stranded passengers from that flight. (Or cover all bases by calling while in line.)

If your tablecloth is wet at dinner, you should prepare for rough seas. Restaurant staffers have been known to slightly dampen the tablecloth to keep plates and glasses from sliding.

Ever since my children were small, I've carried recent, wallet-size pictures of them when we all go on vacation, in case we get separated. Now that they are teenagers and traveling with friends' families, too, I send pictures for the other family to bring along with them. I also write my telephone numbers on the back of the pictures so they know where to reach me in an emergency.

Finding healthy breakfast alternatives at an airport can prove difficult. I always travel with an insulated travel mug. Before leaving home I fill it with a high-protein cereal and then request low-fat milk on the flight.