Pushing The Algorithm

To avoid noise and other artifacts especially while rendering sequences, don't add too much color to the material of the objects you want to use as lights, increase their size instead.
In 2.0+ you have an auto compute button which evaluates the correct settings for FG according to the size of the scene. Once you modify the scene don't forget to recompute.
I suggest that you don't keep the global ambiance (modify>ambiance) setting to 0, instead add a small amount, it will increase the bouncing of colors and better illuminate the scene.
You may try to use several different colored cards for light sources instead of just one this will encourage the light bouncing effect and give more complexity to the scene.
If you require realistic reflections you may want to look into HDRI images as environment maps. Basically an hdri image contains a lot more information than a regular bitmap image. HDR sources can be found here. The HDRI2map converter can be found here.
If you're into games, you can illuminate your scene with FG then use render map on the vertex color to transfer the color to the vertices. The results are quite astonishing. This will transfer the FG samples to the vertex colors of the objects in a specific group or pass giving a whole new dimension to the game. Here is some info for optimizing this process from Dave Lajoie (Project Manager - Rendering) at Softimage.
In 3.0 there is a new pass called Image Based Lighting. This process allows you to use an HDR image to control reflections and final gathering (shade) among other things. A photo real image could be achieved in minutes. The image of the orange capuccino machine was made with IBL.