I never travel without a few Starbucks Via packets in my bag. They are a godsend when I need a coffee fix and don't have time to seek out a coffee shop. My friend Kent Barnes recommended them, and I'll be forever grateful.
The packets are easy to tear open, and they dissolve quickly even in cold water. Sometimes I pour them in a small plastic water bottle, replace the cap, shake, and guzzle. I've mixed packets with cold milk, too. The coffee tastes pretty good, especially if you don't use too much water.
They are popular with backpackers, too.