When you travel a lot there are things you know you don't even realize you know. I suppose it's a bit like any job, from being a mom to making goat cheese to racecar driving: Doing is knowing.

So an oft asked question is, "What do you pack in your carry-on bag?"  Very important.  Though airlines have vastly improved luggage tracking, what's in your carry-on bag may have to see you through your first 48 hours on the road (until your lost suitcase is found).  Or even more critical, what's in your carry-on bag keeps you happy during the flight.  And if it's a long flight and you're in the back of the bus (i.e., coach), it's all on you to try as best as possible to give yourself the upgrade.

ESSENTIALS

Here's what I always pack (all liquids are travel-size, of course) and why:

A happy meal: No, not from the golden arches, I mean something your body is going to be happy about vs. the scary "chicken or beef?" scenario (if you're lucky enough to get offered some food at all).

Strawberry Jim sleep mask: Creates the illusion of privacy, even when you have a stranger encroaching five inches away.

Earplugs:  "What snoring old man?  What screaming baby?  Didn't bother me."

Lug Nap Sac travel blanket: Snuggle when it's cold, doubles as a pillow, and all the germs on it are your own.

Comfy socks: Cashmere is always nice!

Ceramic nail file: Won't set off alarms, works like a charm.

Visine: The best way to fake sobriety or a good night's sleep.

Advil: Or any other over-the-counter pill that takes care of headaches and relaxes sore, sleeping-sitting-upright muscles.

Wipes:  I like the natural lavender ones at Whole Foods 'cause they smell good and they are gentle enough to use all over.  An absolute must in Third World countries or after 48 hours with no shower.

EO lemon hand sanitizer/moisturizer:  I use to laugh at people who use it, now I discreetly pull out my two-ounce bottle.  Like a condom for eating with your hands.

Kiehl's goopy lip balm #1:  Don't want the kisser to be cracked and bleeding.

Pure Fiji body butter:  Don't let the snakeskin effect take hold during the flight! Regular lotion just isn't good enough to combat the desert air of cabin pressure.

Pangea Organics Italian red mandarin with rose facial cream:  Apply once an hour and when you exit the plane, you'll look and feel the same age you were when you boarded.

Evian spritzer: Ditto.  Also gives a nice illusion of ocean spray or rain mist in the Sahara at 30,000 feet.

Tea-tree toothpicks:  Socially acceptable (to some) after meals, leaves a nice tingly taste in your mouth.

Mouthwash:  Easier than trying to actually brush your teeth in those airplane bathrooms.

Emergen-C:  One or two packets a day of this vitamin-C fizzy drink helps keeps the bugs away and puts a spring in your step without the dehydrating effect of caffeine.  I do one everyday I'm on the road.

Raw cashews: Power snack, easy to transport, needs no temperature control.

Lara Bars:  Ditto; satisfies the sweet tooth too.  Also, easy to sneak and eat after you picked politely at a disgusting plate of gray stewed meat (it could be anything or anyone), flipper pie (that's seal -- yum!), or a breakfast of jellyfish salad.

$200 in cash:  To exchange into local currency in a pinch, or for tips or bribes.  I split it between my wallet and passport holder.

American magazines:  Great gifts for new friends in other countries, where these cost a fortune.  I hate to support the celebrity-trash movement, but as a rule, everyone loves People and US Weekly, regardless of whether or not they even speak English.  Plus, they provide a good mindless way to waste 30 minutes on the plane. Vanity Fair takes up a whole hour.  But skip the fashion mags because they are heavy and there is nothing to read per se.

Two novels: Why two? Well because one might be bad.  Or you might need to share one to shut your seatmate up.  And you'll definitely finish one and need a second one for the flight home.

Rough Guides:  Haven't had a minute to read the guidebook before your flight?  Well, it's a great way to kill up to three hours of flying time.

iPod and headphones:  Chances are you can use your own headphones for the in-flight movie too.

Earworms:  If it's a really long flight, I'll download 101 language lessons onto my iPod to refresh my Franglais or Spench (Spanish that slips into French).

Laptop w/downloaded movies:  You only have three hours of battery life (unless you pack a spare), so maybe just two films.  But it's nice to know there's something on standby that you really want to see when the 11th hour of an 18-hour flight is already like Chinese water torture.

International adapter: In case I have a connection and can recharge at the gate.  Notice how everyone has the same idea and there are never enough power outlets though?

Digital camera and USB cord: Be ready to document the banal and unexpected. Or do some transferring to the laptop and edit to make room for the new stuff.

Next blog, I'll talk about what to wear on flights -- and suggest some more must-pack items for your checked bags. Stay tuned.....