Virtual Cell Animation Collection at North Dakota State University was mentioned on the Free Technology for Teachers site and I wanted to highlight it for my readers as well.

You will find a virtual fly-through of a cell and individual videos on a variety of cellular processes such as photosynthesis, transcription, translation, cellular respiration, etc. There are narrated video clips, annotated images, and text supports- a perfect supplement to high school and/or college level life science courses.