There is one more point to be made about eclipses, and I can't believe the ignorance (willful?) on the part of some on this thread about it:
Earth would not be habitable without a moon that could elipse the sun.
The point is not that there must merely be some other astronomical object to eclipse the sun, nor is it that having a moon to eclipse the sun a priori means that there would be life, but that there would almost certainly be no life without such a moon. The Moon stabilizes the Earth's axial tilt. Were the moon much smaller in mass (or much farhter away, therefore contributing a much smaller component to the Earth-Moon angular momentum), *in other words, a moon that also would not eclipse the Sun*, the Earth's axial tilt would oscillate much more, over very short periods of geological time, as Mars' does. The orbital tilt of Mars oscillates on the order of 40 degrees in a period on the order of thousands of years, whereas the Earth's axial nutation (oscillation of axial tilt) is a mere 2.5 degrees. It is our close, massive moon that causes this. Such a moon does not necessitate life, but without it such life would not be possible. That, if nothing else, is the meaning behind the "eclipse" argument. It is no stretch to say that we owe our very existence to our Moon.
There is one other point I'd like to make about the Moon. I make no statements about ID per se, but only to illustrate just how lucky we are to have our Moon in its present form. The prevailing theory of how the Earth came to acquire the Moon involves a collision of some other astronomical body with the Earth, rather than through gravitational capture. The reasoning is that gravitational capture would much more likely result in a moon in a highly elliptical orbit, rather than the almost perfectly circular one it has. Also, it is thought that, were the Moon gravitationally captured, its orbital plane could be in any direction, rather than 5 degrees from the Earth's equatorial plane as it is. It also would have had a 50 percent chance of orbiting in a direction opposite to the Earth's direction of rotation. All of these factors withstanding, most everyone feels that the Moon came about as a result of a collision.
A few years ago a study was performed that involved computer simulations of impacts to try to determine the exact conditions that gave rise to the Moon. Many runs were taken, with variations in the mass of the two bodies, variations in velocity, and variations in angle of incidence with the Earth. Nearly all of them resulted in the formation of two much smaller moons, moons that also would not have stabilized the Earth's axial tilt. In fact, the only scenario that resulted in a single, large moon at the correct distance from the Earth was one in which the Earth was only just grazed by the colliding object.
So not only does our Moon make the Earth habitable, it is also highly unusual. A slight variation in incident angle in one direction would have resulted in a miss (and therefore no moon at all), and a variation in the other direction would have given us two small moons that would have not made our climate habitable. Say what you will about ID, but in any case we are indeed *very* fortunate.