Bioman Biology is a great site full of excellent biology based virtual games, on topics like cells, ecology, body systems, evolution & classification, genetics and meiosis, life chemistry, respiration & photosynthesis and  the scientific method.  This is an excellent way to get students to interact with the information, as each game is loaded with facts and information.  _

I can't wait to use this really awesome online tool called BioDigital Human with my Biology 12 students.
This site allows you to select and de-select parts of the body arranged in systems or regions.  For example take a look at the 3D angle of the digestive system or a heart with angina.