C Crane Company has a really decent led light, the cc trek, that uses 3 AA batteries. I've had one for years and it's still a good light. Haven't looked in awhile, but they use to offer it as a "kit" (as a project for boyscouts and other organizations) where you could save 6 or 7 bucks (by screwing the cap on I guess). They also have a wide variety of LED replacement bulbs, including the Luxeons.

ccrane.com