Good question. All of the meetings I've had so far have been "sorta customer development, but not exactly" meetings... That is, I've been meeting with people who I think are smart, or insightful or connected, or all of the above, and getting some very preliminary feedback. But they - so far - haven't been what I would consider "real customer discovery" meetings, with a specific list of questions to hit on, and a formal mechanism for recording the output.

That said, I'm just now in the process of writing down all of the briefs that @sgblank talks about, and expect to be getting into the "formal" customer discovery stuff in the next few weeks. Once that happens, I do have to do a pretty good job of tracking results, so I've been trying to figure out what a good way would be. I don't have an intern / secretary / assistant / etc. to take notes, and I can't write/type fast enough to take a whole lot of notes during a meeting, without interrupting the flow of the meeting. So far, the best ideas I've had seem to be

A. tape record the meeting, then transcribe the important stuff later. There are some downsides to this: some people might not allow you to record them, the recorder batteries might die, etc. All told though, I do expect I'll try to do this as much as possible.

B. print paper forms (or make a quick Grails app) to record the answers to the pre-known important questions, that I go into the meeting knowing I need to ask. Immediately after the meeting, enter the data for that meeting, before it fades from memory.

Combined with taking brief notes (on paper, or on my phone, or a laptop, whatever) during the meeting, I think some combination of this will work.