We have a ton of airline-academy flight training out of several airports around the Phoenix area. The schools, indy CFIs and the FAA have a
working group to try to coordinate the activity as much as possible. They've set up frequencies for position reporting in the various practice areas, and have published a
chart overlay listing them.
That's all well and good, and very helpful. But I was based here for several months before I even heard about this (thanks to a FAAST seminar). Pity the poor transient pilot who bumbles through the area without knowing the secret handshakes.