Earth and Environmental Sciences, created by the University of Kentucky offers free interactive and animated modules for teachers to use. There are rock cycle, weathering, faults and folds, ground water, river flood and glacier animations, just to name a few! You will need Macromedia Flash or Shockwave browser plug in (free) to see them. http://ees.as.uky.edu/educational-materials  This site is suitable for upper primary and lower secondary students.