This post by Cory Doctorow has got me thinking. He's arguing for blogging as a way of building your knowledge base, but public rather than in private notes. Sharing ideas publicly as you come across them.
I find taking the time to synthesise ideas after consuming them so valuable. I probably spend an hour a day reading stuff on the internet. And 90% of it goes in one eye and out the other. I read it, maybe with a little 'huh, interesting' moment, then move on. Occasionally though, I'll bring something up with my partner over lunch: "I read (x) interesting thing this morning. What d'you think about that?" The stuff we talk about sticks much better than the rest. The act of synthesising ideas you've consumed into strings of sentences that another human can understand help bake it in to the brain.
I can see blogging doing the same.