You may have missed the announcement but John Henderson of 'Artbox Animation and Design' has graciously donated his utility Skycast for use with Animation:Master.
Skycast Tutorials:

1. Using Skycast
2. Skycast in A:M


You can download Skycast via the attachment in John's post.


Why use Skycast?
Skycast creates a rig that forms a sphere or dome rather than have the light come from within the light shape itself.
Unlike similar rigs you can build yourself, Skycast scans the colour of the background image and alters the colour of the lighting to match.

Other methods work well too (Yves' skydomes and Dan Shimmyo or Jeff Lee Skylights for instance) but Skycast tends to render much faster IF you are already using A:M's multipass renderer. For many none of these methods may be needed. A:M's internal Global illumination may be more than adequate.

You can use the skycast technique without Skycast too of course by building your own.
If you are animating or you need to render a scene relatively quickly you can adapt the skycast technique by adding a light inside the model. Create an action wherein the light moves around the room and this will simulate bounced lights in the scene.
Adjust the light to the colour of the surfaces the light is bouncing from and make sure the action/light avoid animated features on it's path.

...or let Skycast create the tools for you!

Optimization
Skycast is designed for between 9 and 25 passes. Set this in A:M's Multipass Render settings.
If Skycast is being used as ambient fill then the number of passes can be reduced.
Using the rigs on multipass settings outside of 9 -25 will slightly unbalance the lighting.


(Apologies for where any of this information is outdated)