"The Oxford Electric Bell does not demonstrate perpetual motion. The bell will eventually stop when the dry piles are depleted of charge"
Yes, and the Earth revolving around the Sun is not perpetual motion, despite the fact that it has been happening for billions of years and will continue to happen for billions more. Score one more for the pendants! :D
I guess the thing that struck me about the perpetual motion line is how unintentionally(?) trollish it was. It invites debate. It would be better to omit it.
It's like a web form that asks your email address followed by "We never ever sell your personal information to anyone!!11!" It raises a question I wasn't even considering and now I'm not sure I trust it! http://goo.gl/PaXG5g
Well, circular motion does not cause any work to be done, so that's not quite the same thing. The earth might continue spinning around the sun forever in a perfect universe, but that still wouldn't violate conservation of energy.
Like tides?
So if motion lasts longer than your lifetime, doesn't it seem like perpetual motion to you? Personally, when I think of perpetual motion, the first thing that comes to mind is using it to power a generator. In that context, if something could produce electricity for decades without being refueled or even attended to, aren't we moving toward and/or operating with a realm that feels like perpetual motion--even if it is only from our self centered point of view? Granted, this is sort of like if someone is in your field of view and then steps behind a tree that obscures your view of them, you can say they are invisible to you. Though it isn't exactly true to say they have gained the power of invisibility, you labeling them as being invisible is a self centered and relative statement.
So as self centered humans, from our point of view any motion which lasts years or even decades--and could be harnessed--could seem sort "effectively perpetual" to us, even though it is nowhere near actually perpetual.
(Yes, this theory ignores that fact that that generator's output would indeed be ridiculously low, probably close to unmeasurable--the important part is that if we have motion, we assume we can generate electricity. And yes, even if you could make this happen, it may take thousands or even millions of these together just to power an LED. I was probably prompted of this thought because of this video: https://www.youtube.com/watch?v=8hwLHdBTQ7s)
For a similarly long-running process, consider underground coal fires. If a seam of coal is burning, it may take hundreds of years to burn itself out, comparable to the lifetime of the ringing bell. But because it is consuming its fuel in a much more obvious fashion, it's less magical.