Fast Company has a nice piece on the importance of taking notes.
As we've discussed before, your mind can only handle so great of a cognitive load--people can only hold so many items in their working memory before they start to fall out. Active listening--that is, attending to the speaker and jotting down the things that catch your attention--lets us invest our working memory in paying attention to the new thing the Facebook founder just said rather than trying to remember that joke he made five minutes ago...
I take lots of notes in paper mole skin notebooks; every week or so I go back with a different color pen and circle the key sentences; I then transfer these ideas to Evernote files on my computer; and finally, I blog/tweet/publish/email out the crispest, most important ideas or quotes.
That's a nice analog-to-digital workflow--one that can help us to attach our experiences to the mental latticework we call knowledge and thus recall info quickly. In this way, we can be productive for the long haul.