I'm pretty sure there was a topic about this already, but for the life of me I couldn't find it. So I figured I'd start another one:
http://dynamic.scrumbleship.com/demoIt's basically a voxel-style spaceship simulator. Right now it's in alpha stage. For now, you can construct your own ship. Eventually you will be able to fly it, fight those of others, run pipes through your ship for fuel, power cells and wires to power individual systems, etc. Anyway, I figured I'd share my own ship here:
http://www.mediafire.com/?zos7ldi1hwn5jm6Just download it, and place the saves folder inside the archive in your install.