Mitch. wrote a review of CamelBak All Clear Microbiological UV Water Purifier - .75L on May 3, 2013
Well, this thing has served me well since I got it in December. I've been in places that are renowned for their disgusting water since then, including Kashmir, Delhi, Kathmandu, and a few cities in China, and not once have I gotten sick. Plus I have the added bonus of using it in public, at which point people say, "Wow, what is that?" and "Does it really work?" and "Whoa Mitch, thanks to this Camelbak product, you are so much cooler and up to date than us". Well, not that last bit as often.
The point is, the battery lasts ages, the thing actually WORKS, the light is pretty when you stare at it, and it's easy to carry, which helps when you have a lot of miles under your belt and many more yet to go. It's so good that I'm writing my first Backcountry review in honor of it.