How many pictures are there of The Face?
Spacecraft orbiting Mars have taken many pictures of The Face. Here are some links to them.
http://mars.jpl.nasa.gov/mgs/msss/camera/images/01_31_01_releases/cydonia/index.html
http://www.esa.int/esa-mmg/mmg.pl?topic=&subtopic=&keyword=cydonia