The obvious solution is to make yet another list: of people that you have lists of things to talk about with (I’ve tried such a system - didn’t help much). Presumably this would indicate to you that somewhere on your iPod was a list of issues to discuss should you run into the person by chance. Of course, you can make lists, jot notes, and set up reminders all you want; eventually you exhaust the ability of this kind of a system to assist you in every scenario. Ultimately, you have to rely on memory at some level. In this case, obviously, you would have to remember to look at this new list each time you encountered somebody unexpectedly to check and see if he or she was on the list.

It isn’t what you want to hear, I’ll bet, but it sounds like you’ve reached the limits of assistance of list-making. It may be that it is time to:

a) rely on your memory

b) be willing to phone or e-mail bob after your chance encounter to talk about that horse should you forget to bring it up in person, or be willing to set up a meeting with bob specifically to discuss the horse.

Finally, your answer to this question may be telling: if the items on the list are important, why can they wait until you happen to run into bob? It seems that, in the spirit of GTD, if you’re not willing to make getting in touch with bob an action (rather than passively waiting to encounter him), you shouldn’t let your list of equine topics lurk around in the shady areas of your iPod causing you this mental overhead.

Thanks man. I think you’re exactly right. Especially the last part. If it’s important enough to write down, then its important enough to actively seek the person out.

Good stuff.

I have similar situation with my work tasks and needing to keep informed with people who aren't always right there or available when I have the question. Here's another possible easy fix:

We are all linked together as teams on Mentat now and if I have a question I just assign a task to that person so they see it too. Of course, this requires that you both use Mentat and have iPhones or BlackBerrys to snap out and check on that chance meeting or convenient time.

Alternatively, you could make a project called "@Bob" for context (using a free personal account even) and set it up to have your questions in there as Tasks, or eventually even have a custom @Bob/questions subcategory. I would put it under "Bug" (meaning I need to bug them about it in this case)in a project for that person if I were to do it myself right this second. ;)

You would still need an iPhone or soon a BlackBerry will work (and later even a cell phone) but if that might work for you, feel free to try it out here:
http://gomentat.com

This post reminded me of the following quote from David Allen’s ‘Ready for Anything’:

“Once people catch on to the power of organization per se, they sometimes go too far and try to microorganize everything: ‘Let’s create a system so you won’t have to think at all!’ But it can’t be done. My systems do indeed relieve the mind of the tasks of remembering and reminding as much as I can, but they don’t replace the need for regular executive thinking about my stuff.” (Chapter 41)

So yeah, I’d say if you’re doing regular weekly reviews of your projects and your next action lists, unexpectedly meeting Bob should be enough to prompt you to pull out your iPod and bring up the list. At some point, you have to trust your brain. As long as you’re regularly reviewing your projects and next actions, it probably won’t let you down.