If you're an active traveler who is happier scaling rock faces and mountain biking than you are lying on a beach, you might want to take along a few packets of E-Boost. This is an effervescent energy drink in powder form (light and easy to pack) that juices you up with vitamins and nutrients.
The company is trying to appeal to the 24/7 business travelers who also love to party: "Between overworking, flying, drinking, doing too much and never sleeping enough, it’s a wonder we can make it through the day, let alone perform at an advantage." If it were aimed at backpackers, you'd have to remove the work part and adjust the need equation a bit. Leave the flying and drinking, but add crappy bus rides, street food, and noisy hostels.
Either way, this energy drink does more than get you hyped up on caffeine. You simply pour it in a glass, add water, and stir. The result is a pleasant orange fizzy drink that made me noticably more alert and awake, but without the shakes. Akin to the feeling you get with coca tea in the Andes, but more with 1,667 percent of your daily vitamin C requirement and enough B12 to meet an elephant's requirement. There's no sugar and only a gram of carbs.
I'm no nutritionist or sports doctor, but my personal trainer wife took these to her gym and they were more popular than Angelina Jolie at a tabloid publisher's convention. Since they weigh almost nothing and take up very little room, E-Boost packets or tablets would be a worthwhile packing addition if you're planning to do some volcano hikes or biking excursions on your next trip. They retail for about a buck apiece and you can buy them at the Boost site, at the W hotel chain, and at hotels in cities where people stay out late and don't sleep much---like Vegas and Miami.