The most common use for a dry bag is, of course, keeping your belongings dry when the conditions around you are wet. If you are at the beach, walking in the rain, in a boat, etc. all you need to do is place whatever you want to keep dry into the dry bag, roll the top a few times and clip it together, just as simple as that.
When traveling you never know what can happen, so having and eight liters (two gallons) dry bag on you at all times could be a lifesaver. As with any good travel gear, it can be used for more than one thing and the dry bag is exactly that.
Here are a couple of ways in which a top rated dry bag could come in handy while you are traveling:
When living out of a suitcase, it can be a nuisance having to separate the clean and dirty laundry, especially if the dirty laundry is particularly dirty or wet. If however, you have a dry bag, this will not be a concern. To save space, roll up your laundry and place it in the bag if you are concerned about odors, just clip the top shut and keep it in the bottom of your suitcase until you set home.
If you have ever traveled, you know how uncomfortable a long airport delay or long layover can be; there are also times in which a hotel may have dubious bedding. During times like these, you will appreciate a pillow. All you have to do is fold the top over a couple of times, clip it together and take a rest. It does not require much air, the pressure from having someone lie on it will compress the bag enough to create a pillow as a substitute.