I was trying to do just this very thing today when, as I was writing an email, I stopped to make an aside about a movie the previous email had reminded me of, that's when I stopped....

That's it!

That's the whole idea. That's what it is. Imagine if all of your asides, your internal/external tangents were all highlighted, hyperlinked and put up on screen for all to see, with the power to follow the strings where ever they may lead.
A rapid transit station for all of our associations.
For this I got an "UMM-hmm." But I think that was a clearer explanation than the one I was working on at the time.