Travel musts for me:
1. Compression bags, I got mine at Target. I use the small bag, pack it to the gills and roll every ounce of air so it's a flat brick of clothes. This allows me to pack 4-5 days of clothes into my 14x17" carry-on. Yes I have to iron everything when I unpack, but it saves me from having to carry a bigger, heaver bag to start.
2. imaingo speakers for my ipod: target.com (not in target stores). It's about the size of an old cassette walkman and it has amazing sound!
3. Clorox wipes. You can find travel sizes in the travel section of most stores. I use them to wipe every light switch, remote control and door handle in the hotel room. Once opened I recommend storing in a sealable plastic bag.
4. built ny bottled water holder (builtny.com). It's made of neoprene and keeps my water colder way longer than without it.
5. In order to keep compliant with the liquids rule I had to find tiny containers for all my lotions and potions. I mostly us the bottles from the carry-on travel kit I got at the bed and bath store, but needed smaller bottles. So I went searching the craft store and purchased a 12 pack of paint pots (like the ones you used to use as a kid). They're tiny and are leak proof.

When travelling by automobile, I always bring the extra set of keys. You never know if the battery in the remote will die enroute and that pesky alarm is quite loud. Also, if someone might lock the keys in the car, it might be quite a stretch to get someone to drive or mail the second set or pays big bucks for the locksmith!! Of course, we keep these keys separated by spouse!

When traveling to a country where I know I will be purchasing breakables, I pack a flattened carry-on bag in the bottom of my suitcase. I use that one to carry home my precious items with me. My other carry-on, with overnight items that I could do without once home, gets checked. If my suitcse isn't crammes, I just reuse the original carry-on for breakables and pack the former contents in the checked suitcase. Either way, my precious items stay with me.

Before departure, photocopy/scan all of your travel documents and email them to yourself at an easily accessed site like aol, hotmail or yahoo.com. Then if you do have your passport or travellers checks stolen, you can easily produce copies of all relevant paper-work and be on the go again with minimum fuss.

Always pack less then you think you will need and have things that are interchangeable.

Always pack less clothing and bring more money.

If I'm not doing laundry the last day of my trip, I turn my dirty clothes inside out. When I get home I don't have to guess which ones are clean and which ones are dirty.

Wrap clothing in plastic bags. The suitcase atop mine had a bottle of (BLUE!) coconut rum from Curacao. The bottle broke and my suitcase still smells like it went to a wild party--but at least my clothing is not stained. Again, never travel with something you cannot afford to lose, and pack lightly. You can always buy something if you need it.

PACK LIGHT

I use the never-ending supply of free return address labels that come in mail to identify my eyeglasses cases.

For years I successfully traveled for business while raising a great family, going to school and trying to keep my marriage on the front burner. I found that keeping all my "supplies" in a complete second set coordinated small bags, always packed and ready made for 5 minute packing. Each item went into the same location of the suitcase. Luckily, I stayed at the same hotel for most weeks on the road. They would see to it my drycleaning was done over the weekend so on my return visit the following week the laundry was ready for me to wear. Paying a small tip to the consierge made sure that I and the clothes were in the same room each week. Not having to remember that floor or room number was awesome!

When I travel I always fill out an index card and put it in my wallet. It is dated , lists the hotel, the names of people I am traveling with, where they can be reached if not with me (such as at the seminar at the hotel- and name the seminar), and phone numbers. You can reuse the card by just changing the date while you are on your trip(so that emergency people would know the info is current) The reason I do this is that you might have your wallet with you when you go for a walk, but if you had something happen that left you unable to remember or unable to communicate, this could be a lifesaver. The numbers in your wallet would all be contact numbers for when you are home, not relevant when you are traveling in another state or country. Emergency people would not know how to connect you with friends/family, and valuable time could be lost .
One other tip: if you want the best info on a town or city when it comes to what to do, ask the head bellman. Usually a native of the city or a longtime resident, he can suggest unusual places to see or great restaurants that the conciege might not know about. Some have given me maps with routes highlighted, for the cab driver, have been very pleased to be asked for suggestions( "I know this city like the back of my hand, and no one ever asks me ") and things they have suggested have been interesting, and lower cost than the ones better known to touists . When I get home I always send a letter to the hotel telling them how helpful he was (I check his name and write it down before I get a cab). I send him a copy of the letter, too, in case the one sent to the hotel isnt shared with him. Concierges have always recommended touristy places which are sometimes interesting, but the bellman give me a taste of the city that is more like the local people experience.

Take along a small bottle of fabric refresher spray. It can help you get a couple of wears out of a shirt or pair of slacks, plus you can spray your dirty laundry and allow to air dry before packing so it's not so unpleasant to unpack!

Wear comfortable clothes such as cotton knits for the flight, but try to stick to a neat, polished look. You never know when you might meet an interesting person or possible business contact on the plane! (Plus, no one wants to feel slouchy in public)

When travelling with a companion or spouse, both of you should not carry the same credit cards. If you carry one credit card, then your spouse should carry the other one. That way if one of you loses your wallet, you won't be without both credit cards. Friends of our had this happen to them on a trip to China. The wife left her wallet on our tour bus. They had to cancel both credit cards, leaving them without a way to charge any items.

Don't pack more than you can comfortably carry

When traveling to China, be sure to take along packs of Kleenex for restroom use. Toilet paper is of course in the hotels, but rarely in public places and tourist sights.

Prior to starting your trip label a large index card with the date and place you plan to be for each day of your trip. Thenwrite out anything you want to remember for that day, i.e. the hotel reservation, sights to see, flight #, etc. If you going on a tour with a travel group, take the itenerary and shrink it down and paste the day's description on the card. Bind all cards together with a rubberband. Each day take that day's card, read the reminders, then throughout the day write journal entries or one word descriptors [whatever your style dictates] about the day. When you come home you can put the cards with your pictures or picture CD and have a fantastic memory packet.

I use the free hotel drycleaning bag to keep my dirty clothes separated from my clean ones in my suitcase.

When packing to go overseas or when you have more than a few clothes, use the extra large sealable plastic bags. Fold your clothes, you can usually get 2-3 blouses in one bag, place inside, seal but leave about an inch open, sit on the bag to remove air, then seal. It vacuum packs the clothes so they take up less room, and when you return, you have a bag to put your dirty/wet clothes in. You'll be amazed how much room you have in your suitcase!

A simple clothes pin will keep the curtains closed tight so that early morning gap of sunshine doesn't wake you up before you're ready.

If you're taking a digital camera on your vacation and are travelling by plane, take a picture of all your checked luggage before you leave for the airport. This way, if it's lost, instead of trying to describe it, you'll have a picture to show.

Download your favorite AUDIO books to your ipod so you don't have to worry about packing a book in your purse! You can listen to it when you're waiting in the gate, on the airplane, or anytime waiting! Plus you can catch up on something you've been dying to read!

When packing clothes, roll them instead of folding. Hang them as soon as you get a room. Less wrinkles!