I found a tidbit on this in the help files. I'm going through a shadows section in my book and it mentions that "some" video cards support the Lighting > Shadows feature. If I create a spot and enable depth map shadows, would the Lighting > Shadows option turn on and be available for me to click? Mine stays shadowed out. I'm using the nvidia FX1100 card with Maya 6.0.
Yes it will work with the quadro fx 1100. You have to be viewing lighting in the viewport first. All lights or selected lights hotkey: 7. Then you should be able to turn the shadow on. You can also use Hi-resolution shading in the viewport.