Data Structure Visualizations
I wrote a web site http://gregfjohnson.com/redblackbuilder.html that takes interactive algorithm visualization another step.  I would be delighted and appreciative if people go check it out and provide thoughts and feedback.  IMHO It is fun and informative to play with, and a great tool for learning the algorithms.It is specific to red-black trees, but I am considering adding other data structure manipulation algorithms as well.On insert and delete, you can single-step forward and backward and see the tree manipulations at each step.  Or, you can do the entire operation at once.There is pseudo-code for insert and delete, and at each forward or backward step the line of code being executed is highlighted.