I was thinking of my top five list of things that I take with me when I travel, things that add comfort and convenience to life on the road.
1: 10 foot long charging cords for my phone and tablet. Increasingly there are outlets where you need them, but not always, go online and order extra long cables, carry more than one charger.
2: Travel toiletries kit, I keep this seperate and packed all of the time. I use full size things like tubes of toothpaste and keep duplicates so the kit always packed and ready to go. I keep a mini kit, in the messenger bag that I carry all of the time, all I have to do it top off a couple of medications in that mini-kit and I am ready to roll.
3: Passport, and backup ID. One rainy night in Atlanta after I missed the last flight home, I misplaced my driver license in the bottom of my briefcase. Having my passport as a back-up allowed me to get home the next morning. I found my divers license the next day when I dumped my briefcase out.
4: Extra cash and a back-up credit card. I keep a travel wallet with cash and a credit card in it. The first time I was in London my ex- had a pocket picked. I discovered the next day that the London Zoo does not take American Express, fortunately I had a back-up card. (I keep Euros on hand, ready to travel at a moments notice.)
5: My Kindle and a tablet (I-Pad.) I read when I am flying, it passess the time and enriches the mind. With my Kindle I can take a dozen books in the space of less than one paperback. My I-Pad has become indispensable when I travel, I have a keyboard case so it doubles as a travel computer.
In addition if I am renting a car, I take a GPS unit, you can try to use your phone, but a dedicated GPS unit is much more useful.
What do you not leave home without?