Ever since I saw the peculiar, foam-like arrangement of galaxies, I was intrigued. Here is an example of what I'm referring to. Every point of light in this image is an entire galaxy.
This inspired me to create a fly-through visualization that lets you explore nearby stars, galaxies and galactic clusters. Please be patient while it loads all the data, there's 4MB of galactic cluster data and 2MB for the stars, so it takes a minute or so the first time you load it.
My favorite is the "galaxy" view - you can see the clustering of galaxies, and you can more or less see the filaments and voids. The "cluster" view may not quite be correct yet, and the radii and brightnesses could all use some work. But it gives you a sense of where we are in the universe, which was its purpose. If any programmers or astronomers feel inspired to help, the code is here.
For a more visually gratifying fly-through, here is one based on the terabytes of data gathered by SDSS:
Here's a great little demonstration of the scales involved:
And I can't help but include a link to this article about what might lie beyond the meager confines of the observable universe: