My
Pelican Nemo 2010 is also 3 x C-cell. It's about as big a light as I have a use for. It's waterproof to several hundred feet and explosive environment rated, too (although I don't remember to what level). The "Recoil" system fires the emitter backward into a reflector that focuses the light and sends it out the front. When I bought it I was amazed at how bright it was but it was the first decent LED light I'd ever seen!
Of course by today's standards it's not all that bright (I mean compared to a Surefire, etc.) but it's plenty bright for anything besides "tactical" use. The big draw of the
Nemo 2010, aside from being waterproof, is the battery life. It claims something like 30-40 hours, and I've been using the same set of batteries for maybe four years in the thing and it's still going strong.