[SFF]

As you said, I use Folders for the 20,000 ft level of Areas of Responsibility (Work, Household, Friends&Family, Photography, Career Development, Personal Development, etc). Within each folder are Projects.

You are correct in that some of my Folders do only contain 2 Projects - a single action list and a Someday/Maybe list. While some may consider it silly to have a folder with only 1 or 2 projects, I find that the hard, visual distinction of ALL of my top level (20,000 ft) Areas of Responsibility being shown as a Folder makes a lot of sense for me. It also gives me visual indication showing where I may be "light" on projects and may want to concentrate future thinking (i.e., Work and Household are a bit heavy right now, and I only have 2 projects in Career Development -- Maybe I need to put more energy into that Area!).

Also, having all my Areas of Responsibility exist as folders gives me a match for how I set up Evernote and Curio. I have both of those applications set up with exactly the same folder structure as OmniFocus. The top level ("Notebooks" in Evernote and "Sections" in Curio) match my Folder structure in OmniFocus, which allows me to easily store reference material (Evernote) and Thinking/Planning/Brainstorming material (Curio) in the same mental construct as my 20,000 ft Folders in OmniFocus. Also, I have additional Sections in Curio above my Areas of Responsibility (namely, the 30,000, 40,000, and 50,000 ft Horizons) for additional brainstorming space.