Living Alone, Older, or By Yourself A Lot?

Something that I just thought of -- if living alone, by yourself a lot, or uh.... 'older', create a system of communication with a network of family, friends, and neighbors that you trust so if they don't hear from you within an established time frame, they can start worrying about you and do the necessary things to make sure you're OK. You don't have to divulge in details, just send a sign that you're fine.