Diane,
You have touched on something very relevant to each of us as educators- the true need for additional resources out there proprietary to our niche fields of study. Though there is a wealth of information out there, there are many untapped areas that demand attention. I know publishers such as Pearson and Cengage are feverishly working at identifying and developing these materials, and there is a great need for subject matter experts in many fields. For many Adjunct Professors, this is a viable revenue stream worth looking into.
Wishing you continued success in the classroom.
Theresa Schmitt