Okay, I've read several different ways of creating space scenes for sci-fi games, but I am truly at a loss as to what the best way is. A mapped sphere or cube never comes out exactly right, pinching in the sphere and a bit of distortion from the cube. I have read that at least in the original Freespace they used openGL lines to draw stars and that wouldn't be a bad solution, but I still feel there ought to be a way to do it better. What I'm looking for is that Eve Online look or even Homeworld with the sweeping nebula and bright points of light. I'm thinking that there should be a way to do this programatically, but I can't figure it out. I'm using NDL's engine, btw, if anyone has experience with it. Thanks in advance.

Is there a way to split a sky/horizon texture into 6 faces for use in a skybox in photoshop (with clamping, etc..)?

As this is for a space game to create sky cube textures just create 6 blank images fill them with black and put some stars, nebulae, planets etc on them. Depending upon your artistic skill you can end up with something that looks great.

For stuff like nebulae that you actually want to be part of the 3d environment, you could use something like billboarding or a partially transparent mesh with some clever texturing or a static particle system.

this(free reg required) article may give you some ideas on how to do a glow effect as well.