Because I fly a lot, I even maintain an "Online" action list, separate from my "At Computer" one. When I'm on a plane, I can't easily connect to the Web or to my server, as many actions require. So instead of having to rethink what I can and can't do whenever I look at my "At Computer" list, I can trust that none of my "At Computer" actions require that I be connected, which frees my mind to make choices based on other criteria.
Think carefully about where and how you can and can't do which actions, and organize your list accordingly.
If you have a computer only at work, you may not need a separate "At Computer" list; "Office Actions" may cover those actions because the office is the only place you can do them anyway. (Similarly, if you have a computer only at home, and it's not a laptop, you may be able to put computer-specific actions on your "At Home" list.)
"Errands" It makes a lot of sense to group together in one place reminders of all the things you need to do when you're "out and about." When you know you need to get in your car and go some-where, it's great to be able to look at the list while you're on the road. Actions like "Get stock certificates from safety-deposit box," "Pick up pictures at framers," and "Buy petunias at nursery" would all go here.
This list could, of course, be nothing more elaborate than a Post-it that you keep in your planner somewhere, or a screen in an "Errands" category of the "To Do" section on your Palm organizer. It's often helpful to track sublists within individual "Errands" items. For instance, as soon as you realize you need something from the hardware store, you might want to make "Hardware Store" the list item and then append a sublist of all the things you want to pick up there, as you think of them. On the low-tech end, you could create a "Hardware Store" Post-it; on the high-tech side, if you were using a digital list, you could attach a "note" to "Hardware Store" on your list and input the details there.
We must strive to reach that simplicity that lies beyond sophistication
— John Gardner
Because I travel in major metropolitan areas so much, I keep two "Errands" lists — "Errands—Ojai" (where I live) and "Errands—Anywhere," for all those other things I can pick up even when I'm on the road. "T-connectors for irrigation" would go on "Errands—Ojai," but "Get dress socks" would go on "Errands—Anywhere."
"Office Actions'/"At Office" If you work in an office, there will be certain things that you can do only there, and a list of those will be a useful thing to have in front of you then—though obviously, if you have a phone and a computer in your office, and you have"Calls" and "At Computer" as separate lists, they'll be in play as well. I'd use an "Office Actions" or "At Office" list for anything that required an Internet connection available only, or even most conveniently, in the office—for example, a reminder to download a large software program from the Web would go on this list for me.
"At Home" Many actions can be done only at home, and it makes sense to keep a list specific to that context. I'm sure you've got numerous personal and around-the-house projects, and often the next thing to do on them is just to do them. "Hang new print," "Organize CDs," and "Switch closets to winter clothes" would be typical items for this grouping.
If you have an office at home, as I do, anything that can be done only there goes on the "At Home" list. (If you work only at home and don't go to another office, you won't need an "Office Actions" list at all—the "At Home" list will suffice.)
"Agendas" Invariably you'll find that many of your next actions need to either occur in a real-time interaction with someone or be brought up in a committee, team, or staff meeting. You have to talk to your partner about an idea for next year; you want to check with your spouse about his schedule for the spring; you need to delegate a task to your secretary that's too complicated to explain in an e-mail. And you must make an announcement at the Monday staff meeting about the change in expense-report policies.
Standing meetings and people you deal with on an ongoing basis may need their own "Agenda" lists.