   LoadIdentity() or PushMatrix()
  what's the difference between just loading a new identity and pushing/popping a matrix?  which one would be better?   
  glPushMatrix() pushes the current matrix down one and duplicates the matrix. As in the matrix at the top of the stack is still has the same values as before the call. glLoadIdentiy() replaces the top matrix with the identity matrix, effectively destroying all transformation information thus far stored. They do two very different things.   