Depends on what you mean by ghost effect

You could lower the opacity of the layer, use inner or outer glow as layer effects (maybe set the glow colour to white), plus you can brush over areas with the eraser set to a low percentage, or the brush tool.
Did you mean to bring the two outside images together and have the face burning through the blue? Or are you going to rub out the blue...fill it in?
Must get around to doing a sig of my own, and/or making use of the one aiwazz made for us too
