It's highly possible that you may own one of those rechargeable flashlights, that sits plugged into an outlet when not in use. While you may not have to worry about its batteries being dead when you finally need to use it, it does spend most of its time occupying an outlet, doing nothing. MoMA's Bulb Flashlight, on the other hand, doubles as an LED light bulb.
The Bulb mounts in any standard screw-type fixture, and uses six watts of power to produce a light output equivalent to that of a 40-watt incandescent bulb. As long as it remains in that fixture, it stays charged.
In the event of a power failure or some other flashlight-requiring situation, the user just unscrews it, extends its handle, flips on its power switch, and there you go – semi-instant flashlight. It's reportedly able to run for three hours before requiring recharging, and its bulbs should last for at least 60,000 hours of use.
The Bulb Flashlight is available now from the MoMA (Museum of Modern Art, New York) store for US$45, or $40.50 for MoMA members.