I just added this to the HID pcb: http://www.delorie.com/pcb/puller/
It uses the same math I used for my "pullit" optimizer sample (http://www.delorie.com/pcb/pullit-sample.png) but it's manual. You have to set up the arcs manually, then the "Y" key adjusts the angles to make the line tangent. Enjoy! PS: yes, I know undo and redraw are messed up afterwards. It's just a proof of concept.
