There was a time in my organizer life when my main goal was to avoid duplicating or re-writing information anywhere, ever! I thought making duplicate entries meant that your system had failed. Now I'm a lot more open-minded on the subject.
For example, my company uses Google Calendar, so all my work-related meetings are in there. I keep my personal appointments in a Personal organizer in both DPP and Wo1P formats. But I've started putting some personal appointments in the computerized work calendar as well. After all, my co-workers need to know not to schedule me for a meeting when I'm at the dentist!
And, believe it or not, I've started also writing my work appointments on the paper DPP. That way, I can see them when I'm away from the computer.
So, what's your philosophy on keeping information in more than one place?
Of course, since it's Friday, all other ring-bound organizer discussion is welcome!