Our planet is indeed infinitesimally small in relation to the overall size of our galaxy, and our galaxy is only one among billions of others.
All of which makes you realise just how daft it is to believe that alien spacecraft from another galaxy have been visiting us for decades, or even centuries.
It's sometimes hard to accept that we're alone in the vastness of space, (and perhaps we're not, if you consider the chances of life existing somewhere else far out in the universe), but the fact is that for all intents and purposes we can forget about having a chat with an alien culture.
Enjoyed both links and it certainly does put things into perspective. For Blackhat's link I highly recommend listening to Holst's Mars (from the Planet Suite) or the Star Wars Imperial March.
As Douglas Adams once said, "Space is big - really big - you just won't believe how vastly, hugely mind-bogglingly big it is. You may think it's a long way down the road to the chemist, but that's just peanuts to space."