Gary,
First, my mistake, I meant TPS and not MS (which I joined 2 years ago).
The Moon is an unlikely place to colonize, because it's far too hostile, agreed. And it would be very useful for science. Now, I wonder about a number of telescopes in space (for optical interferometry): Could they be more stable than on the surface of the Moon, knowing those telescopes (located far away from each other) would be under the gravitational influences of not only the Earth, the Moon, the Sun but also Jupiter, Venus,etc...and different influences at different times(solar wind,etc)?
Perhaps, but it sounds like far more challenging than the Moon as a platform.
To colonize Mars?
Well, we haven't colonized the poles, the oceans on our own planet (when we could).
While 38% is higher than 16% gravity, I'm not at all sure somebody who has spent 6 years on Mars would have no problems returning back to Earth or somebody born on Mars could ever visit the Earth.
Besides, colonizing a place has entirely different objetives than exploring it.
The idea of colonizing Mars has a lot to do with the early settlers in the new world, but technology is advancing so fast that I'm not convinced we'll colonize any world in the future, at least in our present shape and human form.
We want freedom, we want to reach out but we also want to be able to return (that's entirely part of our need for freedom); remaining under a glass dome, or a huge O'Neill like L5 colony are not really an expression of freedom (like not being physically capable to return back to Earth).
That's why I'm not really thinking too much about colonization. BUt it's certainly interesting to debate about it.
Regards,

Raoul