Emily Chang jumped into an interesting discussion of one piece of personal knowledge management with My Data Stream (emphasis mine):
After a year and a half of using social applications heavily, I recently had to revisit the plan to aggregate all my activity into one data stream. As the calendar rolled to 2007, I kept wishing I could look at all my social activity from 2006 in context: time, date, type of activity, location, memory, information interest, and so on. What was I bookmarking, blogging about, listening to, going to, and thinking about? I still had the urge to have an information and online activity mash-up that would allow me to discover my own patterns and to share my activity across the web in one chronological stream of data (to start with anyway).
The rest of the post is her adventure in finding / building a data stream to do this.
Chang is focusing on data streams: stuff she is reading or posting online that as a RSS feed attached to it. But the idea of expanding this to include documents I've read / modified / created on my desktop and my other browsing activity would be the direction to go.
The thing that keyed my interest is the link to personal knowledge management. Why? If I am able to see context in which I was operating, I can recreate in my head what was happening and what I was thinking. Sometimes it may just be one thing, but other times it takes more memory triggers to remember the setting in which I found a particular item interesting or why I wrote what I did.
People have been looking into this "digital memories" concept for quite some time. Microsoft have a project on digital memories and IBM have the MyLifeBits project. Communications of the ACM had a series of articles last year (Jan 2006, vol. 49, no. 1), on which I commented.