Robin Good: PKM or Personal Knowledge Management may be indeed a very close relative to Content Curation. But while Content Curation, is done with a specific audience in mind, PKM is done for one's own learning.
Harold Jarche, looks at the relationship between the two and writes:
"The most important part of personal knowledge management (PKM), in my opinion, is the need for active sense-making.
Merely seeking and sharing information does little other than create more noise online.
Sense-making takes time, discipline, and effort.
-> One strength of PKM is the “manual” nature of sense-making activities. The act of writing a blog post, a tweet, or an annotation on a social bookmark all force you to think a bit more than clicking once and filing it to an automated system.
-> Sense-making, or placing information into context, is where the real personal value of PKM lies.
-> The knowledge gained from PKM is an emergent property of all its activities.
Merely tagging an article does not create knowledge. ...
The difference between PKM and Curation is that the former is personal, while the latter is for an intended audience."
Full article: http://www.jarche.com/2012/07/pkm-as-pre-curation/