http://www.edheads.org/activities/simple-machines/

http://www.mikids.com/Smachines.htm 

http://www.simplemachines.net/

http://www.cdli.ca/CITE/machinessimple.htm 

http://edtech.kennesaw.edu/web/simmach.html 

http://library.thinkquest.org/J002079F/sub3.htm 

http://www.lakelandschools.org/EDTECH/Machines/Machines.htm 

http://www.ed.uri.edu/SMART96/ELEMSC/SMARTmachines/machine.html

http://appliancehelp.com/resources/Simple-Machine-Lesson-Plans.aspx