The resistance band is one of my favorite exercise equipment for when I'm traveling and on-the-go. Cheap, lightweight and portable, they definitely easier to shlep around than dumbbells and can provide a decent strength-toning workout. And it's definitely reassuring to know that there's one in my baggage, so I won't feel stressed looking for a gym out-of-town (that charges a fair price) and I feel less compelled to "slack off" during vacations.
They're great for home workouts too, since I can exert as much (or little) force as I want -- some days I might want to test my other strength to the max while other times I just want to do some easier moves for toning and adjustments, or to give my cardio workouts a little extra oompf.
So something to keep in mind when you're traveling next time or just looking for a light-to-moderate toning workout. For some nice basic moves you can do with the bands, check this out.