The one thing I wouldn't travel without is my combination alarm clock/sleep machine. It is very compact and takes just 2 C batteries. Besides showing me the time and waking me up, it also functions as a sleep machine which blocks out noise when you're try to sleep. You can choose from different sounds like rain, waves, waterfall, etc. If you are rooming with a snorer, it helps with that; or, elevator and people sounds outside your door; ship cabin creaking or anchor sounds; airplane noise if you're staying near an airport; etc. I just couldn't travel without it. And since you don't plug it in, you don't need to worry about the current or finding an outlet near your bed.

Diana San Diego, California