Glad to see more people using panels. I've heard good things about the Calumet panels and your method of hanging them is simple and inexpensive. I like it.
With very large panels another great and inexpensive solution is using 2 Super Clamps (get the Impact rather than the Bogen because they're exactly the same and $5 cheaper) and 2 light stands. Just mount the Super Clamps on the 1/4"-20 thread on the top stud of a lightstand and tighten the Super Clamp to the vertical poles of the frame. Then just lift to the desired height. This does require 2 people to lift into place and tighten so redbutt's method is a great solution with meduim to large panels because it can be setup and adjusted with one person.