It sounds as if you're well prepared to take a note at any time. For that, I use the same tools you do: Scrivener, Moleskine, and digital recorder.
So our tools are the same, but I add two bits of process: First, I always transcribe notes from the Moleskine and recorder into my idea file in Scrivener. All of my notes quickly end up in one place.
I've been experimenting with iPhone/iPad apps instead of my Moleskine notebook. Yesterday I was on an airplane and had an idea. I fired up PlainText (which synchronizes across devices and computers via Dropbox). But because I was not connected to a network, PlainText spit up some kind of warning or error, which I dismissed. I was able to create a document to take my note, but by that time I'd forgotten the idea.
So for now I'm likely to forego newer technology in favor of paper.
A second bit of process: In Scrivener, I often tag my ideas. For non-fiction, I tag them with topics. For fiction, I tag them using the CLOSAT scheme (Character, Location, Object, Situation, Action, Theme). Over time, this scheme alerts me to some interesting patterns, e.g. that most of my ideas about about situations, some are about themes, and very few are about characters.
By always transcribing notes to one place, and by tagging my ideas (when the tags are obvious), I give myself the best chance of finding ideas when I need them.