Not really, but I might try "hey kitty kitty" as an alternative to a fishing rod and bait in the future.

Thanks for the idea.

Rolf Harris is making a modified versions of his wobble board modified for resonance at RF frequencies. If you go to his official website listed under references the FAQ describes how to construct your own.

Actually anyone can ask for it, you can just decline to provide it and it's illegal for them to insist on it. You don't have to disclose it to an employer or financial institution, in which case they withold tax on your income at the highest rate marginal tax rate plus any other applicable taxes. If you have income that's already been taxed at maximum possible rate that leaves no chance of "avoidance".

I suspect you're quoting the cost of replacement is $250 rather than the battery itself, and I think a lot of people underestimate the cost of labor involved in doing those operations in an industrial environment. Something that takes two minutes on a bench often involves several people, down time, climbing and safety gear and for some applications would actually exceed that amount.

Piezoelectric elements are common and can be made in a pretty arbitrary size, most are actually smaller than that device. I guess a regular moving-coil microphone could be made fairly small and would generate power. I've seen some pretty small SMD photodiodes and I'm sure they'd be many other examples that generate power, albeit in tiny amounts.

Nothing in that article seems too pie in the sky to me, they are talking about a target of 100 microwatts afterall, not charging your iPhone while you go for a jog. Unlike a lot of other articles the target applications listed seem like fairly plausible applications for the technology.