Thanks, i'll try both methods. I'll elaborate a little on why i asked this. I have a scene with some simple animation going on in it, but I also have a large complex object in the scene as well. I just need to be able to render the scene quickly to get a guage on how the animation looks. But at the moment I have to wait ages because of this complex object in the background.
So I suppose my question is really, not only do I not want it to appear in the scene, I don't want it to be considered by the renderer at all, so that i can quickly render the scene. Then when everything looks ok, re-enable it to have it render with everything else.
If either of the methods you guys suggested has this effect, then just disregard everything i just said!