I answered "I operate on a friends layout using car cards or paper", although technically I operate only occasionally on the layouts of several different people in the area, most of whom I've made contact with through the local NMRA group. Like Doug, I visited the Operations Road Show layout recently. If you have a chance, check it out. It's definitely a learning experience.
According to the February SCALE RAILS article, they have had to paint a lot of the models for Wabash. Almost makes them honorary Frisco modelers. I saw one of the ORS guys at a local show going from dealer to dealer looking for GP-7s. "Back Home Again In Indiana" is a great tune and should be their theme song.
I was having more fun that I appeared to be having in that photo. Seems they caught me scowling at the clock, or something....
On a large layout I can see this working, but I run an N scale hollow-core door layout with semi-hidden staging (for the one daily local to hide in). A switch list for the local and one for the mill switcher is pretty much all the paperwork I need. To this end, I have a small pile of ready-made switch lists (with the Frisco logo, natch) for each train. I probably need to have some sort of building for a local agent somewhere.....perhaps a metal shed, since there's no room for a depot. FTR, I have operated on layouts that were equipped with CTC panels and full signaling, and that was pretty neat.