I’ve decided on the Princeton Tec Byte Headlamp. $20 cheap. Claims 35 Lumens. 2.25oz including the easily replaceable 2 AAA batteries.
Read the Gear Junkie review.
_____ original post from Aug. 10th:
The other day I was mocked by Adventure Racers for calling my wimpy Petzl a “headlamp”:
… only good for reading in the tent!
Actually, that’s all I use a headlamp for while on the trail.
Any recommendations for something with more lumens? Something (still lightweight) that would be useful in scrambling mountainsides in the dark?
Here are some recommendations from Backpacker in 2010:
Lightest & Cheapest
Coast LED Lenser Micro HeadlampSteady Burner
Mammut Lucido TXlite HeadlampBest Light Quality
Petzl Tikka Plus 2 HeadlampBrightest
Black Diamond Spot HeadlampBest All-Around
Princeton Tec Remix Headlampdetails on Backpacker
Warren suggests the SoLite 150. $179 !!
For cycling he’s very happy with the Light & Motion Vis 360 Front and Rear Helmet Bike Light System.
besthike.com 
Hi Rick:
Just to throw in something completely different. I bought a new biking headlight 1+ years ago. Light&Motion360. Hiking lights are wimpy, and probably need to be so: battery life is more important than brightness. However, biking lights need to be bright. This thing is amazing. Tiny, light and bright. Compare the specs to anything else you can find for hiking. I keep it on my intermediate (spring and fall) helmet full time. This exact model is probably not for hiking (rechargable lithium battery, via USB).
http://www.rei.com/product/808602/light-motion-vis-360-front-and-rear-helmet-bike-light-system
Hmmm, looks like they have a hiking version. Much heavier with much longer battery life.
http://www.bikelights.com/solite150.html