Generating 2D image from a 3D object

How would I go about generating an image or material of some kind from a 3d prefab?

Take a screenshot of it then crop it down to what you want? Or, if you can open the model externally, render it and output it to an image file.

I was thinking more along the lines of real-time generation. I decided to just render the 3d object as is for the hud.

This is only possible with Unity Pro because you would have to render to a texture. If you have Unity Pro, have a look at this.