Catwalk construction for Truss installation

I am going to start putting up the roof trusses for my new construction right after Christmas. I came accross an article on truss installation by Larry Haun. Rolling Roof Trusses - Fine Homebuilding Article (http://www.finehomebuilding.com/how-to/articles/framing-with-roof-trusses-no-crane-needed.aspx) From the article, I really like the idea of building a temporary catwalk right down the middle and feel it will really help with the installation. I would appreciate some ideas on how to build something similar, ideally by just using 2x4 and 2x6. Thanks