Y'know, all that "conservation of angular momentum" stuff is all well and fine in the lab. But it doesn't work that way in the real world.

(Yes, a politician actually did say that. Forgot who and where, though...)

- Jake

Austerity can only be implemented in the shadow of a concentration camp.

Actually the accusations are probably true. Wind power can slow the motion of the earth. Using the forces of the tide definitively takes its energy from the rotation of the earth, and the more friction the tide has to overcome, the more energy gets lost from the rotation.
But with ~ 10^26 J stored as rotation energy, this is not a short term issue to worry about.

However, I think you can run some distance in front of the tide, to speed earth up again. The trick is more to be in the right position to the moon, than to run ultra fast.

Der Amerikaner ist die Orchidee unter den Menschen
Volker Pispers