About the "why would an advanced alien race bother with us?" argument/question:
From what we know of our galaxy, life isn't exactly sprawling everywhere. If it were, we probably would've made contact some time ago, assuming we're a young species. Let's entertain the idea that this alien race is one of the few out there.
Now, as far as their intelligence goes...from what we've seen on our own planet, even some of the most vary different species have common organs. Brains, hearts, livers, kidneys, etc. From studying life on our planet we know that us humans have one of, if not the largest brain size in proportion to our bodies. Sheer gray matter isn't everything, but it makes a big difference. Taking a look at the stereotypical gray alien, we see that their brains are probably quite big. This leads us to believe, that if all life is at least somewhat similar, that they are essentially much smarter than us. Probably hundreds of thousands of years of evolution ahead of us, which does make it interesting as to why they would bother with us. Of course life may not be as similar as we see, and their large brains might not mean they are hundreds of thousands of years of evolution ahead of us. It could also mean they have mastered genetic engineering and pushed the fast forward on their evolution. Don't laugh at the idea, we're getting to that point ourselves, but society isn't ready to let us play god.
So why would they be interested in us? As far as technology goes, we've harnessed the power of the atom (atomic blasts are easily visible from space), we're within decades of exploiting the massive energy potential of anti-matter (read: the most effecient form of energy known to exist - matter is converted completely into energy), we're exploring space, showing heavy curiousity. I don't think it's a coincidence that UFO sightings have gone through the roof since World War II (atomic weapons).
Then there's our medical technology, which you must admit, is pretty impressive. People can go their entire lives without a single fear of dying from disease. We're on the verge of huge medical breakthroughs, limited only by our own society. You don't need to be able to read newspapers to tell that - just look our population growth. Within the next few hundreds years we'll be needing to start colonizing other planets.
We also manage to almost destroy ourselves over and over, only to end up thriving in the end. Who knows if this is a unique trait among intelligent life, nor is it something to be proud of, but it is interesting, and to alien life it could say a lot about us. For one, our weapons technology might make us a force to be reckoned with if we ever move out among the stars. Let's assume that they are no super energy shields like in sci-fi, because even the most far fetched physics theories say the energy requirements would be far greater than even things like antimatter, and that's ignoring the problem of manipulating the energy, and that's ignoring the fact that energy probably won't block matter, and won't block other energy which is on the correct wavelength. Granted there's a lot we don't know, but if aliens ARE interested in us, it does suggest there aren't many radical things in science to be discovered as there were, say 200 years ago. The more answers we get and the more we can back up our observations with equations and theories, the less likely there will be more major scientific discoveries. Major scientific discoveries being, like, oh, let's say one day we find out everything we thought we knew was wrong.
We're clearly intelligent, we're clearly trying to explore, and it's pretty clear we are trying to advance. I think that would make us quite interested to alien life, especially if the galaxy is as scare of life as we think it is.
Oh, and to comment on "how/why would aliens travel so far to observe us"...well, there are a lot of theories on faster than light travel which don't violate relativity or quantom mechanics...warp propulsion (folding space around you) is one. There's also the newfangled idea of interdemensional travel, like hyperspace. Suggesting that, if I recall correctly, there are more than 3 spacial demensions, but they're so small that they can't be noticed. If you could move into one of those demensions, travel a short distance and pop back out, you might find yourself on the other side of the galaxy. I can't explain it, the other spacial demensions kind of confuse me. All I know is that I read it on a Wikipedia page about string theory, which call for there to be 10, 11 or 26 spacial demensions according to their equations. Perhaps someone like Mort-Hog could explain it better.
There's also the possibility of generation ships. Or these aliens could have long lives and be very patient. However, that doesn't help to explain the frequent visit phenomenon - aliens visiting, leaving and coming back. Unless they have a base setup somewhere in or near our solar system that we can't detect.
Bassoon, n. A brazen instrument into which a fool blows out his brains.
