Oh right, my comment before about "rolloff", what I meant was...
take a look at this picture:
http://t2.gstatic.com/images?q=tbn:ANd9GcQefe3b19NzjIt7lZX2GxSN4V9hqxxIhKo0OgmCafk-kgR7uphy&t=1See the kind of, hard shadow it makes?
Then look at this one:
http://t2.gstatic.com/images?q=tbn:ANd9GcQoCaGt1WoIrIzdbPl5ZM01QtI77dX3C9O6U5M0M1z2BRBDMf-w&t=1... it's not a great example, but see how it kind of fades out? Think we can get that effect on our lights?