Ive noticed that when you want to get vertices/edges/polys lined up, you click on one and copy the axis co-ordinate then paste them into each other vert/edge/poly individually.
There's a much quicker (and less hassle) way by just selecting all the vertices and clicking "make planar" (either x, y or z depending which axis you want them aligned). This aligns them on the axis so you dont need to do any copy/pasting of co-ords.
