I've got this week's topic down. As someone who likes to travel and who has kids, I've had ample opportunity to learn what's worth having in that bag that serves as my carryon on the plane, or stays up front in the car.
1. Sunscreen - I wear it every day, and if I'm going to be somewhere sunny (basically anywhere other than where I live), I apply more than once a day. I usually use a sunscreen/moisturizer combo on my face, so that's also good for combatting dry air in a plane.
2. Camera(s) - Vacation is not a time for phone photos.
3. Cords & chargers - I always have cables and chargers to spare so that the entire family can charge their devices while we are on the go. I had a cool charger that allowed multiple USB cords to be plugged in, which was super handy when we were in spots where there weren't a lot of outlets available, but it died a couple of weeks ago. I think I'm going to have to get a replacement soon, as that charger spent its non-vacation days in our family room, where the entire family could charge their devices in a central location.
4. Wet Ones - This is something I got from my grandma. I always have a canister of Wet Ones in my car, and I bring it on vacations where we will be renting a car. And I always have a smaller pack in my bag when we travel. They are awesome for cleaning up life's little messes, sticky fingers, and even spills on clothing. If it's hot, they also feel nice and refreshing on your neck or forehead.
5. Knitting - Well, of course!
(Photo from this summer's vacation - the sunscreen, water, and camera were very handy on our climb.)
6. Book(s) - I really do not like to read on my iPad. I will gladly tote around a book or two for vacation reading.
7. Altoids or other mints - These are good for airplanes, but everyone seems to like having them around most of the time.
8. Lip balm - I've got lip balm stashed all over the place (except in the car, where it will melt). It's one of those things that I don't like to be without. When you need it, you need it right away.
9. Bottle of water - Always good to have, even though it's usually someone else who ends up drinking my water.
10. Headphones - Strangely, having headphones so that I can listen to something I want to hear is not my top priority in carrying these. Usually, I end up giving them to one of the kids (who forgot theirs) or using them myself to drown out the noise of someone else.