There are some tutorials in this thread that show you how to add decals and such to textures using the material room.  Scroll down and look  for "Node Masks".

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2722867

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi