IRIS this is a great website and has been improved even since the last time I visited. It has many educational resources including lesson plans, activities, downloadable animations and videos on everything plate tectonics. I first learned about this website while field-testing an inquiry-based earth science curriculum call Foundation Science: Earth Science. EarthGuide is a website I just located that I had to add here too. It is an online classroom from California that has many things Earth Science including plate tectonics with animations and tutorials. Also check out PBS A Science Odyssey Mountain Maker Earth Shaker.