The Habitable Planet
This is a great collection of multimedia Science resources, including lectures, notes, videos and interactives.
Get on and have a go!
It is produced by Learner.org, a huge and excellent resource for all Science topics (and other subjects, too).
NOVA Life Science Resources
NOVA from pbs.org (Public Broadcasting Services) has a great library of animations and interactives on their site.
Topics include Evolution, Classification, Genetics, Ecology and Microbiology.
Many of the interactives can be saved using the downloader on Firefox.