Face to Facebook is when you don't have time to call or get together in person with friends or business contacts, but you still want them to feel special, so you write on their wall.
Hey no big deal. I wish I had time for a face to face meeting too but I am so slammed that I can't make it until late next week. We can Face to Facebook until our lives calm down a bit. If you need immediate attention, you can always go primitive and I'll pick up.