Wide-mouth plastic water bottles are a common sight during outdoor adventures, and so are lanterns ¡ª but this is the first time we've seen them brought together. The Firefly by Guyot Designs ($22) is an ingenious little device that attaches to the mouth of your water bottle and uses an integrated LED to turn your bottle into a glowing lantern. Luckily, should you have an encounter with any hostile wildlife, the brightness is adjustable.
