The University of Chicago at Boulder (http://phet.colorado.edu/) offers simulations in just about all science areas to increase understanding in the area a student is having trouble with as well as in math. For the science activities, they show things having to do with Biology, Chemistry, and Physics. The simulations can be used to reinforce understanding of things learned in class. The best part about it is the fact it is free. An example of this is in the Physics section. The activity is ‘Wave on a String’. It falls under ‘Analysis’ in Bloom’s Taxonomy because students will use it to point out the parts of a wave, and to analyze how the wave actually moves. All of the activities on the website are the same way.
This is a print screen of ‘Wave on a String’ from my personal Flickr account: http://www.flickr.com/photos/briannadoyle/6315109295/in/photostream