In short, if you keep an inbox (in the Getting Things Done (GTD) sense), consider collecting into both sides of it as follows:

1. things you come up with - add them to the top
2. things the world sends you - add them to the bottom

and then always process your inbox(es) into your next-actions etc. from top to bottom.

This works for both physical inboxes (trays) and digital inboxes (e.g. text files).

The source of this insight for me was threefold:

• GTD collection order is unspecified. GTD does not specify an order for collecting things, just that you do collect them first (rather than reactively doing them), into as few inboxes (ideally just one) as possible, and batch process them later.
• GTD processing order is unspecified. GTD also leaves unspecified the order of processing items in an inbox - top to bottom, reverse, pseudo-random - it doesn't matter, or so it says.
• Freedom is a measure of how you spend your time. Similar thoughts have pre-occupied me for a while (per The Acceleration of Addictiveness vs Willpower, Productivity, and Flow). Free will is fundamentally about the conscious prioritization and time you spend on what you want to do vs what anyone else, or anything else, demands of you.

This isn't just about your self: this is about your thoughts, your will, and what you care about. For example, you might think, my parents (insert other loved ones) matter to me, I should give them a call, but maybe it's not a convenient time to do so, or you're in the middle of doing something else. So collect that thought, right into the top of your inbox.

Contrast: anything you get in the mail (someone else sent it and is demanding your attention). Or some object of yours breaks or needs maintenance (you have spares or backup plans/devices right?). These are good examples of things to collect into the bottom of your inbox. And what about email? Well, email is not your inbox, and if anything you should "process" it (if you can call it that) after you've processed your explicit inbox.

And with that, I'm going to call my parents, as that now happens to be at the top of my inbox.

Afterword: I was about 2/3 done writing this when I saw the news on Twitter about Steve Jobs stepping down as CEO of Apple. Even though he's remaining as chairman of the board, the message is clear: Steve is done taking an active role in driving product design at Apple, and will (hopefully) be taking time to take care of himself now first and foremost.

It's far too easy to fall into the habit of fitting into a system with all of its pressures, assignments, duties, and roles. Steve was in the rare situation of being able to do both, fit into a system and drive it / make it implement his will.

Few of us will ever have such an opportunity. That is, for the rest of us, we have to constantly choose what and who to pay attention to, our own thoughts, desires, and will, or that which the world thrusts upon us?

I think it is possible to prioritize, process (and follow-up on) your own thoughts first, and still keep up with interacting with the people and things that matter to you.

As usual, this is a productivity improvement work in progress. Your results may vary, and I'd like to know how they do. I encourage you to iterate upon anything you've learned here, and publish your findings and improvements publicly.