Staying hydrated while traveling is essential for maintaining your health. Drinking contaminated water is a quick way to sabotage your health and ruin your trip. Bottled water is a surefire way to avoid drinking contaminated water, however it's also a quick way to burn through a budget (not to mention contribute to the ever-growing Pacific garbage patch). Fortunately, the Grayl Ultralight offers a solution. The compact design conserves pack space and is easy-to-use. What's more, it both purifies AND filters water; other similarly-priced systems will only do one or the other. That means it will remove both larger particulates and microorganisms such as viruses and bacteria. I used it while hiking the Salkantay Trail in Peru with no problems at all.
Tip: Because the Grayl is only able to purify up to 16oz at a time, I would recommend bringing an additional water bottle to fill up. The Vapur Element is a great option for conserving pack space. Also, if your trip is longer than a month I would recommend bringing replacement purifying cartridges along.