I just recently bought a River Rock 0.5W LED lantern at my local Target after reading a review on
Flashlight Reviews . It uses 4AA and gives about 8 hours of
regulated (i.e. steady, not gradually dimming) output. I haven't used it long enough in one sitting to verify that 8 hour runtime, but I'm sure it's in that neighborhood. The light is bright although with some distracting artifacts, but some people over at CPF seem to like using Glad Press 'n Seal to even out the light. The globe does not heat up much.
I bought it primarily for blackout use as an area light, but it feels quite solid and seems reasonably well constructed and should stand up well for outdoor use. No variable output, but there's also a flashing mode, which is very bright, and could be useful in an emergency situation. I recommend it--and only about $20!