Obadiah by G. Michael Cocoris is a 19 page expositional and homiletical treatment of Obadiah.  It includes an expositions of the 3 natural literary units of the book. Obadiah is available for $4.00, plus shipping and handling.

The chapter titles are:

Life is Not Fair (1:1-9)

People Are Not Fair (1:10-14)

Is God Really Fair? (1:15-21)