Energizer's "Light on Demand" LED Rechargeable Lamps
Energizer's "Light On Demand" products are LED lamps with battery backup, able to operate for up to 20 hours when the lights go out. And because they're from a battery company, each of the light sticks' batteries can be swapped with regular alkalines. Three products are designed to be plugged into an outlet: a desk lamp, a tabletop nightlight, and a wallplate nightlight. A motion-activated light and a wall sconce have to be recharged at a docking station.
I initially thought all the products in this series used a single type of lamp, but since different models have different listed running times when they're switched to battery power, I guess the only real innovation is that these are always-charged LED lights.
If your lights go out often I could see these being really nice. It is irritating to discover you're in a blackout but have forgotten to keep a flashlight around. That said, I can imagine that the majority of these lights will never be used as flashlights making the built-in battery superfluous and wasteful.
Target will have the retail exclusive on these until late summer. Prices have not been announced and the official website is down. (Would it be rude to suggest a battery backup for their webserver?) Update: Energizer tells me the prices will be "$24.99 - $69.99."
Press Release [PRNewswire.com via OhGizmo]

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It's unclear from your post--Do these lights, when plugged into a powered outlet, charge standard Ni-MH rechargeable batteries? I currently use rechargables primarily for my Wiimotes, but having the charger double as a flashlight would be a definite bonus.
Claud, I am not sure, but I suspect they would work like that since they use a standard-sized battery and Energizer sells a line of NiMH rechargeables. But I didn't see anything about that specifically.
If they can be set to act as emergency lighting, coming on automatically when the power goes out, I can definitely see some use there. (Granted, I already have an old flashlight that works that way when plugged into the wall.)
I just posted a review of this product here:
http://overwhelmedwithjoy.blogspot.com/2008/06/win-free-energizer-light-on-demand.html