Videos can give an immediacy to science topics which can't be experienced directly. I recently used a video on the rain forest and another with current information on the planets. Many of our students are visual learners. I work with a small group in the library encouraging them to brainstorm, make a semantic web, and predict before viewing the video. Then we watch a short segment of the video, stop and discuss.
Video is wonderful because it is so easy to stop and replay.
Careful observation is one of the key components of good scientific study. These short science videos are especially useful for classroom teachers who don't feel comfortable with hands-on science. The videos actually demonstrate the experiments. We have Pollution, Insects, Endangered Animals. I've noticed much more interest in science school-wide since the library became more involved in the science program.