I was playing with Google Video and came up with some videos produced by the WT Society in American Sign Language:
http://video.google.com/videoplay?docid=2892237581858336163&q=watchtower
This will start a video. There are others linked in a box on the side.
I don't necessarily recommend these but they may be of interest to some here. I have to say, though, that the quality of the ASL used in the videos is quite good.