Zooming in DVD Player!
I only discovered this feature in the Leopard version of DVD player. It might also be in Tiger, but I never used it and I don't know where it is (please post about it in the comments if it is possible in Tiger). What this feature lets you do is zoom in on a movie in DVD player. I find this useful because I sometimes have poorly encoded DVD that have black bars on the top and the bottom or on each side. If your display doesn't fit the aspect ratio of the encoded DVD and black bars were included in the encoding, you end up with black bars all around and a smaller picture in the middle. The zoom feature is available in the full screen controls, just above the timeline. It is the third icon from the right. It will let you zoom while keeping the aspect ratio or if you disable the "Lock Aspect Ratio", stretch the image (stretching the image is not really the best option).