The lighting where I do most of my gun cleaning, scope mounting, etc. is just awful, and the workspace is such that there's little I can do as a renter to improve things. Then I discovered the Stylus Pro from Streamlight. Powered by two AAA batteries, the Stylus Pro's high-flux LED bulb helps me see inside receivers, check the fit of driver bits and do other detail-oriented tasks, and the pocket clip keeps it handy. I haven't hit limits of the 71â'„2-hour runtime despite several months of use. It retails for about $16.
I've also been using Streamlight's PolyStylus in ultra-bright green LED (red, blue and white also available) for nighttime navigation in hunting lodges, hotel rooms and the like--and to find things in vehicles and daypacks in the dark--without ruining night vision. Also about $16.