Is the Moon inhabited?

Our moon has been an object of fascination for millennia.  Many beliefs developed about it through time and it was a largely mysterious presence in the sky for the majority of our history.  Even though we eventually got to the Moon (or so we're told) there are still a number of mysteries for us to uncover.

Strange lights, clouds, and mists on the surface of the moon have been observed for hundreds of years with no real explanation behind them.  NASA itself has acknowledged these mysteries and has recorded many reports of strange activity on the moon from the age before spacecraft.  Strange lunar phenomena visible from Earth continue to the present.  Strange tracks and objects have also been photographed on the Moon since we've been sending probes there.  There are also the rumors of an extraterrestrial base on the far side of the moon to contend with as well.

Most people are aware of the big fuss that was made over the "Face on Mars" several years ago, but fewer people seem to be aware of the very strange things happening much closer to home.  Perhaps the strangest thing about the Moon is that there is a theory that it is actually artificial and functions as a very large spacecraft.  This theory, called The Spaceship Moon Theory, was developed by two Russians in 1970.  This theory draws together the more interesting lunar anomalies into one theory that makes a scary amount of sense when looked at.  Some of the anomalies that the theory addresses are the bizarre density and mineral composition of the moon as well as how it got into Earth's orbit in the first place.

So, what is up with the Moon?  Is it a giant spaceship?  If so, where is it from?  More importantly, who was operating it and are they still there?  It just doesn't seem like the Moon should remain so mysterious in our day and age when we've actually sent people to its surface.  Are these mysteries largely ignored by science or does someone have the answers and just isn't sharing them?

Here is some additional reading about the mysteries of our moon.

Strange Things on the Moon
The original Spaceship Moon proposal.
Some Say Moon Photos Show Signs of Alien Life