http://www.longacreracing.com/products.aspx?itemid=1798&prodid=7218&pagetitle=Caster+%2f+Camber+Gauge+w%2f+Magnetic+Adapter

Longacre is good stuff used by racers.

I had a friend who set his toe using plumb bobs. I approximate the setup on a flat piece of concrete using a carpenter's square and marks on the concrete.

R.