More Gravitation sites

http://www.physics.buffalo.edu/gonsalves/ComPhys/Chapter4/oct8.html

http://www.pas.rochester.edu/~blackman/ast104/newtonkepler.html

http://einstein.stanford.edu/Media/Newtons_Universe_Anima-Flash.html

http://www.physics.purdue.edu/class/applets/phe/keplerlaw1.htm

http://www.physics.purdue.edu/class/applets/phe/keplerlaw2.htm

http://www.cuug.ab.ca/kmcclary/goodjar/image.html

Fun with gravitation:

http://arachnoid.com/gravitation/

http://arachnoid.com/gravitation/small.html