Stupid ZSphere question

I'm using Image Plane 4 to add a reference image to my canvas. All I want to do is draw a straight line of ZSphere's down the length of my model. Every time I attempt this though, the additional sphere's never come in perfectly next to each other alone the same axis. They always come off slightly in front or warped in some manner because I'm not selecting the exact side of the parent sphere. Is there some sort of magical snap button I can use for this? There has to be a way...

EDIT: Shift seems to do the trick. Derp. Make sure you pull out the sphere THEN hold shift. It will then snap to the same size, then you can pull/scale how you want.