A topic heavily debated by lightweight backpackers is the necessary or appropriate light source to carry while backpacking. What to carry depends on environment, use, and the comfort zone of the hiker. Some will claim a simple Photon Micro-light (http://www.photonlight.com/) is plenty. Chances are, those people merely need a simple lightweight option for camp use as it wouldn't be practical to use for nighttime hiking. Others prefer to use one of the more substantial headlamps on the market such as those offered by Petzl, Black Diamond, Princeton, and others.
My personal comfort zone and hiking experience has caused me to carry both a Photon Micro-light and a Petzl e+LITE headlamp (http://www.petzl.com/). Yes there is some redundancy which is likely unnecessary, but I wanted the option to hike in fairly mild night conditions which required a headlamp as my Photo Micro-light simply wasn't enough and I didn't want to burn out the batteries on the e+LITE for simple camp chores because they aren't replaceable. After some recent night hikes, I found everything worked as planned, but I felt it would have been nice to have something a little more substantial as the e+LITE isn't really meant to cast enough light for legitimate night hiking.
The problem with "substantial" headlamps is that they aren't as light as I'd like. I also find many have completely unnecessary skills and function buttons that do everything but function easily when needed most. Yes, some are better than others, in fact some are quite impressive, but I wanted the most bang for my buck in a lightweight package. With that, I wanted to keep my options open to both a traditional headlamp and other options - like a flashlight.
Backpacking legend Andrew Skurka (http://www.andrewskurka.com/) turned me on to the Fenix LD01 flashlight (http://www.fenixlight.com/) a couple years ago and is worth discussing.
The Fenix LD01 provides a maximum of 85 lumens at only 14 grams (excluding a single AAA battery). It offers three brightness settings: 9 lumens (11 hours burn time), 28 lumens (3.5 hours burn time), and 85 lumens (1 hour burn time). It is made of aircraft-grade aluminum and made well at that. The cree LED is expected to last for 50,000 offers which is quite an achievement for a very powerful light. It is waterproof, comes with a removable pocket clip, key ring, and spare o-ring. The LD01 also works with lithium batteries which means a longer and more consistant burn. It likely can also be swapped out with other items that use the same battery, like a camera.
Overall, I really love this light. It is powerful, durable, made very well, and is small and light. I highly recommend it. Now if Fenix would only come up with an ultralight hands-free way to carry it (other than my mouth), that would be ideal.