On a sunny day (Wed, 22 Oct 2008 11:40:22 -0700) it happened John Larkin wrote in :
>I bet an AM antenna would collect plenty enough power (in the city) to
>run a green LED.
You could modify one of these, put it under the mattress, and have it charge a supercap,
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so every time you get up [or move LOL] you get some hour light.