What I've learned about Personal Knowledge Management (PKM) I have learned socially, informally and "non-formally" too (See Harold Jarche's @hjarche PKM Workshop opportunity in @C4LPT's Social Media Centre). Mostly I've pulled my understanding from a knowledgeable network of people of my choosing. Recommendations of people have been presented but not in a traditional formal method. My network has grown through the unconscious actions of those I've deemed as influencers. They, by their acknowledgement of others as providing value, have surfaced new voices and I then welcome them into my Personal Learning Network (PLN).
PKM to me is about having a plurality of voices and ideas; driving the knowledge, pushing it ever forward through additions, subtractions, and modifications. Knowledge is fluid. The personal decisions we make by selecting those we listen to and interact with have the potential to change our understanding constantly, as it should, for today change happens more quickly than ever; we are on Internet time now and have been for some time.
The tools we use must align to our own comforts and match the flexibility of our very human processes of connecting, collecting, and sharing of this information. For me, they must be simple so as to not siphon much needed mental energy away from what is most important, the new ideas that impact my work. Some tools offer more robust capabilities but do they add value?
PKM must happen constantly... it should become subconscious, an involuntary action. Today there are no longer barriers to when and where your PKM efforts happen. Mobile devices, access to a PLN on which the sun never sets, and a plethora of tools allow knowledge management efforts to be continuous. There are no excuses.
As powerful as PKM is, it can also quickly become overwhelming. The keys to success are, in my opinion, simple and internal (as Harold reminds - personal) - Identify what you want to know, find and connect with those who will help you know it and stay diligent.