I currently have about 30 Areas of Responsibility for work and 20 for personal. These include everything from "maintain professional office space" to "maintain contacts" and the more job specific areas like committees I sit on, programs I'm responsible for and policies/procedures I want to ensure are maintained and relevant. For personal I have roles like "Me", mom, wife, etc but also medical care, finances, musician, writer, appearance etc.Average for most people is about 5-10 personally and professionally, but it's unique for everyone depending on your life and level of granularity you want to drill down to.
When I first implemented GTD a lot of these Areas of Responsibility lived on my Projects list, but after some reading here at the forums and some trouble trying to identify NA for some of these I realized that something like "Maintain Personal Appearance" is not a project. During my weekly review I see this entry on my AOR list with some brief descriptor words ("hair, nails, clothes, accessories") and I may generate a project ("Get hair cut", "shop for new winter boots") or I may acknowledge that I feel this area is getting along just fine and no new projects or actions are warranted.
For me, the Areas of Responsibility generate projects, which generate next actions. I found that when I seriously culled my "Project List" to get rid of anything that was really an "Area of Focus" it clarified a lot of my thinking.