Got my skydome make today. Just using a place holder texture at the moment until I create my own. I followed a tutorial on 3Dmotive.com to create the mesh and it also tells you how to create a texture from a panorana picture using polar cordinates.
I also found a tutorial from a webiste called 3dbrushwork.com. This tutorial shows you how to create a material that allows you to create an instance of that material to change parameters such as having moving clouds, colour of the horizzon line, colour of the sky and even having stars so you can animate a day night cycle.
This is a shot of how the material looks when its completed.
This shot shows my current settings. I have it set up to resemble a night sky with the moon behind some clouds.
This is a shot of what my sky looks like at the moment. I have a dominant directional light in the scene that casts a faint moon on the skydome. I made it very subtle as its behind the clouds and set the brightness to a low value.