ESO has released a 108199x81503 image of the Milky Way.
You can download the image as a Photoshop file from ESO.
Unfortunately, I haven't found any way to view this image on a Linux machine.
I've found a version in raw RGB format, but gimp can only view the first 2G of this file.
I've created two small C programs, one that splits the file into 1024x1024 tiles, and one that displays the image using these tiles. The generated tile file is 34G bit, as it containes scaled-down tiles as well.
The source code for the programs is available as esoview.tar.gz. You'll need OpenGL and glut to compile the programs. They only work on 64 bit machines.
Have fun, Mogens