It's been too hot lately to go camping, but I'm planning on camping sometime this fall. And if there's one item I don't want to leave home without, it's Guyot Designs' Firefly.

Invented by Eric Goldfarb, the Firefly is a lid with a built-in LED that fits wide-mouth bottles from GSI, Nalgene, Outdoor Products, Cyclone and Stansport (I tried it on a Nalgene bottle). You can think of the Firefly as a night light, trail light, and lantern all-in-one! Mostly made from glass-filled nylon, the top of the Firefly contains a tether, which is handy for hanging it from your tent. To use it as a table-top lantern, the three grips let you stand up the Firefly so that the light shines up. 

To power the Firefly, simply press and release the orange button at the top. To activate different levels of light, press and hold the button, then release it when you've reached your desired light level. To turn it off, press and release the button once. Shown here is the Firefly lit during the day, and it lit at night.

Can you pour hot liquids in to the bottle, and will it affect the LED? According to a company rep, "hot liquids should be fine, but because Firefly is compatible with many different bottle manufacturers, it's a good idea to consult with your specific bottle manufacturer's recommendations. The liquid temp shouldn't affect light level...I've also heard of people having fun with different things - like iced tea with ice cubes or clear water with lemon slices for a cool, lava lamp effect. Experimenting is half the fun."

I added water and some slices of lemon to the bottle to see the effect, and you can view a photo of it here.

Overall, everyone here at the office thinks the Firefly is such a practical and cool product, and they want to use it for their next camping trip! Plus, the lid doesn't really weigh down the bottle, so it's still light enough to carry, even with liquid in it.

Purchase the Firefly for $21.95 (bottle not included). Three AAA batteries required.

I also took a look at another Guyot Designs product: the Gription. Also made up of glass-filled nylon, the Gription is a lid with a leak-proof internal seal and a locking valve so you don't have to worry about spilling your drink while hiking. Just hold the trigger down to take a sip, and then push the lock pin in to seal your drink.

I liked the big handle, and the hole in the middle is for a carabiner so you can attach the bottle to your backpack. It's a bit more heavy than the Firefly, but it's still pretty easy to carry. The Gription sells for $12.95 (bottle not included). View photos of the Gription here.

Updated 8/15/06 to clarify compatible bottles and what the Firefly and Gription are made of.