Easier Pin Connection Point

[drampulla]

A nice feature when laying out a diagram would be: hold down the Ctrl key when dragging a line and this would have the effect of temporarily pinning the connection point that is on the opposite end of the line that you are manipulating.  
I find that it would be easy to go to one side of the line and pin it, and then go to the other end of the line and move it a little to get it to layout nicer.  Since I never remember which is the start or end point, I frequently pin the wrong end.  If the ctrl key caused the opposite end of the line to be pinned, then I could just move around the interesting point without worring that I'm moving the starting point.