Realistic looking Earth
Again, I followed a tutorial from Blenderguru. Additionally to the original tutorial, I added some stars in the background using a wallpaper. The stars feature in den World-Settings made the stars flicker when I was moving the camera. That is a known bug in Blender which isn’t fixed for years.
And, I was adding something like a sun. The sun isn’t perfect, maybe I will improve it somewhen later.
PS: If you have problems with the .blend file: It was created with Blender 2.61 beta.