Some rendering packages do not have the ability to snap a light to the camera, so I have provided the attached ruby script to help you align a camera light.
Download IRender_align_camera_light.rb and place it in the SketchUp Plugins folder.
[Edit: uploaded a new version with trace replaced by printf]
How to use a Camera Light
Step1 - create camera light

Create a component with one or more lights in it.
The origin of the component should be in the location where it will snap to the camera.
The blue axis will be aligned to the line from the camera to the eye.
The green axis be aligned to the cameras up vector.
The red axis will be aligned perpendicularly to the up vector - usually left and right of the camera.
Place any geometry or attributes in the camera_light component which will help illuminate the scene. (The construction lines will not effect the scene)
Do not place any geometry which will obstruct the camera.
Save the component as 'camera_light'
Step 2 - place camera_light component in a drawing

It does not matter where you place it, it will be snapped into position when you align it.
Step 3 - Align Camera Light to camera

Camera light placed in the model
(Zoomed out a bit so that we can see it).
Select Align Camera Light from the plugins menu.
When aligned properly you will not be able to see it.
For testing, it may be handy to zoom out to let you see how the camera has been placed.
Step 4 - Render model with camera light

Scene rendered with camera light.
(Zoomed out a bit. Normally the camera light would not be visible)
(Rendering made with IRender nXt)
Tips
* Two or more spotlights will usually provide the best effect.
* Normally the camera light will not be your only light. It is intended to augment other lighting.
Try it out
Try this our with your renderer and let us know how it works.
