As far as I can tell, I've finally nailed a system for keeping track while working - keeping track, that is, of ideas which persist on trying to storm the cranial gates and take the brain by storm, thereby making the land in which I am trying to sow, tend, and reap some very specific OTHER idea than the marauding ideas. I think these notepad sized post its are going to be the magic weapon - the freeze you where you stand so I can come and get you later power of the wand. (And that castle is a coloring page you can download - just click on it)
In the comments, Nell asked about a recording device. I invented one, actually. (scroll down to the Thinktank) It got honorable mention.
But the problem with the Thinktank is the necessity for transcription. I can't use a recording device if I do not also have a secretary. So ... it doesn't solve my original problem.
But this notepad system, now. This is just tactile enough for me (actual paper and pens are involved), just flexible enough (and a blessing on all the descendants unto the seventh son of the seventh son of the person who invented stickum that doesn't stay stuck), and just portable enough (in a pinch, I could grab the handful from one whole category to take with me on the way out the door).
Now I need a big dry erase board to stick them to so I can draw lines for the category places and take other notes. And I think this is going to be the topic for my Problem Solving paper. After reading Dan Crowe's How I Write, I have been looking for my own best Idea Generating Situation. After taking Problem Solving, I barely even feel silly at all for needing it.