Designer Kyuho Song has designed a portable straw humidifier with the purpose of being available anytime, anywhere. The design emulates the form of a drinking straw and works by being put into any glass of water.
Portable Humidifier - USB powered / attaches to any bottled water. As long as you re-used the bottle and didn't add to the landfill collection of plastic, I think this'd be a great idea for travellers.
19 Insanely Clever Gifts You'll Want To Keep For Yourself