No one knows more about sidestepping vacation aggravation than the world`s most traveled people, whose combined journeys total 12 million miles. Here, six items these veterans won`t leave home without, from a device that may have saved one man`s life to a household item that`s the key to a comfortable flight.

We love to travel, but we`ll be the first to admit that a vacation doesn`t always turn out the way we anticipate. No one knows more about preparing for the unexpected than the world`s most traveled people.

Finding such folks wasn`t hard we started by visiting the Travelers` Century Club, which limits membership to people who have visited more than 100 countries, and ended by calling on the Most Traveled People, whose checklist for members includes 872 locales, including "territories, autonomous regions, enclaves, geographically separated island groups, and major states and provinces."

Before you start packing for your next adventure, consider their advice you just might want to make room in your suitcase for a few of these items.

Jane Pringle: Visine eye drops you never know when you'll need them.
Years spent traveling: 45
Countries visited: 47
Frequent-flier miles: too many to count! (46,000 at present)
I make sure I have a small bottle of Visine eyedrops. Sometimes on long flights, or in strange places, the eyes get red and don`t cope too well, and the Visine helps them relax. This was extremely useful when we were traveling in Bhutan and the spring pollen was in the air. Without my Visine, I would have suffered terribly.

Hinrich Kaiser: One word: DreamSack.
Years spent traveling: 40
Countries visited: 78
Frequent-flier miles: over 1 million lifetime miles with United
I like to travel with a silk DreamSack. It is an item I`m used to that feels comfortable and is lightweight. (Made by ecofriendly, Oregon-based Yala, the DreamSack is a cozy, person-size pocket with an attached cover for a pillow. It`s made of 100 percent silk and folds up into a little bag for travel. From $62 at yaladesigns.com.)

Matthew Kleinosky: My water filter. It has saved my life.
Years spent traveling: 35
Countries visited: 60
Frequent-flier miles: 95,000 with United; using 90,000 with Delta this week
A water filter. I take it carry-on. One can get stuck on a plane, in an airport, or in between at any time. The filter probably saved my life in India, when I was stuck for most of a day, and bottled water had run out there. I also carry a flexible, roll-up, one-liter water bottle that I fill (and filter) once I get past security at every airport.

Harlan Sager: I won`t leave home without my Swiss Army knife.
Years spent traveling: 48
Countries visited: 41
Frequent-flier miles: 1,298,387 with multiple carriers
My first aid kit and my Swiss Army knife (in checked bags): I`ve used the knife to open items, to eat, and for other useful functions. And I have applied a quick-freeze cold pack from my first aid kit to the ankle of a lady in North Korea, who had sprained it badly on a hike.

Don Parrish: A bed pillow is essential.
Years spent traveling: 46
Countries visited: 191
Frequent-flier miles: 3,392,376 with United
Five years ago, I started traveling with my bed pillow (in a light nylon case). This means that regardless of the type of bed I get in a hotel, my neck is comfortable, and I sleep better. In economy seats on long flights, I strap my pillow to my front using the seat belt. This way, I stay warm on cold planes and can rest my arms on my pillow, which helps me to sleep.

Keith Crocker: Earplugs and a sleep mask are key.
Years spent traveling: 28
Countries visited: 80
Frequent-flier miles: about 300,000 lifetime miles with Alaska Airlines
Earplugs and a sleep mask are essential. More often than not, I am seated by loud, unhappy children or someone who keeps opening the window shade throughout the flight, and I generally prefer to sleep as much as possible on long flights.