When I started this blog, I figured it would be useful. But it's not. It's proved to be incredibly valuable.
It wouldn't be quite accurate to say that my Budapest talk was written just by going through the blog, picking out quotes, and stringing them together using ideas I'd just tossed up in the occasional post; but it certainly was a lot easier to write the talk, having this digital notebook to draw upon.
I haven't actually given up on paper notebooks, but I find that I tend to write more about the organization of the book, and the management of the project itself, on paper. I do some Big Thinking on paper, but increasingly the bits and pieces start out in digital form, and stay there.