You can't win
You can't break even
But maybe, just maybe, you could get an interesting and highly entertaining conversation piece for a very reasonable price.
At first glance these reproductions of perpetual motion machines through the ages seem to be impossible, but a glance fails to realise the discrete motor and power source within it.
All the "workings" of the device are clearly visible, while the bit doing the actual work is hidden inside. Popular designs for these ornaments include:

Over balanced wheels (With free-rolling cylinders display stand).
Robert Fludd's - Waterwheel and archimedean screw.
Johannes Taisnerius' - Magnet and ball.
Mark Anthony Zimara's - Windmill and Bellows.
-- fridge duck, Oct 26 2005

Waterwheel http://www.kilty.com/graphics/fludd.gif
[fridge duck, Oct 26 2005]

Overbalanced wheel http://www.strangeh.../20020819/first.jpg
[fridge duck, Oct 26 2005]

Magnet and ball http://www.chem.uns.../magnet-machine.jpg
[fridge duck, Oct 26 2005]

Make it a museum collection; the visitors to Gull Hall of the International Museum of the Unlikely provide a never-ending stream of energy, walking on a floor of cleverly disguised weight-drop panels, piezo mats, what have you.
-- elhigh, Oct 27 2005


Then exhibit with great fanfare the halted incoming electricity counter for the facility. Ha!

[mfd withdrawn. I didn't understand at first that these were deliberate fakes, rather than models of honest attempts that just took a long time to wind down. Sorry, slow.]
-- jutta, Oct 27 2005


I've deleted my annotation as well now. You're going to delete that annotation and make me look foolish again aren't you :)
-- hidden truths, Oct 27 2005


This the post of the perpetually revolving annotations.
-- ldischler, Oct 27 2005


I have not yet posted the anno that I will withdraw later, but I don't want to be left out.
-- normzone, Oct 27 2005


The only perpetual motion is that of human minds wrapping around half-cocked shemes.

[+]

(I wonder if there's any way we can work a Sisyphus model in?)
-- shapu, Oct 27 2005


and I thought a perpetual motion was what you got after a nasty vindaloo.
-- xenzag, Oct 28 2005


"Lisa, in this house we obey the laws of thermodynamics!"

-Homer Simpson, in response to Lisa's perpetual motion machine.
-- MikeOxbig, Dec 18 2005



random, halfbakery