Armed with just pen and paper as no computer was up to the job, for three months Lion Kimbro wrote down every thought that came into his head. It left little time for much else. Now, was that necessary?
...Why would anyone in their right mind want to do this? "Because of the incredibly clarity that comes with it," Lion says. "It may feel that for the first time in your life, you really have a clear idea of what kinds of thoughts are going through your head. I wanted to see if I could make myself smarter, by strategically placing notes to myself. Intelligence, as I define it, is getting the right information at the right time at the right place, towards whatever end you are going for."
He's got instructions for how others can do the same -- download the guide.
I agree that you can make yourself smarter with the right info at your fingertips -- it's why my white coat weighs about fifteen pounds. But I'm not sure mapping every single thought provides much insight. You've got to separate the wheat from the chaff. There's got to be a happy medium between ignoring your ideas and obsessing over every fleeting thought... I think blogs exist in that zone. And the hyperlinks are a nice bonus.
A nice discussion is underway at Mefi, including a comment from an old apartment acquaintance.