Ask HN: What types of systems do you use to convert information into knowledge?

I’m guessing many of you out there may have a great many interests and consume a huge amount of information from many sources everyday. Do any of you have formal or quasi-formal systems in place to convert that information into knowledge instead of having it just passively wash over you and remain as trivia and tidbits? Find bigger themes, connections, etc…

Note-taking systems, active reading, Evernote/Onenote, mind mapping, essay writing, blogging, whatever… What works for you?