Neat site for virtual tours of cells. http://www.cellsalive.com/
Take a look through a virtual microscope! http://www.edgate.com/d.pl?url=http://micro.magnet.fsu.edu/primer/virtual/virtual.html
Your Gross and Cool Body! What makes your body work? Find out here! http://yucky.kids.discovery.com/noflash/body/index.html
Virtual tour of the human body. http://www.medtropolis.com/VBody.asp
Another virtual tour of the human body. http://www.kidshealth.org/kid/body/
Discover how these cool sound effects are made! http://pbskids.org/dragonflytv/knowhow/knowhow_sound.html