alt s shrink /flatten

how do I use this tool
lets say, I extrude two faces from a sphere and want flatten them in the x direction.
how is it done?

I think I ask that wrong, if I extrude 2 or more faces on a sphere those faces will not be flush with each other.
in other words I want all the verts. to be aligned so all the faces are flat with each other, like a cube with subdivided sides.

Alt-S + X . X twice if you want to do that in the local instead of global coordinates .