Dandelife.com : Story : "Lifecasting - Dandelife Streams", by Kelly Abbott
Ross Mayfield's Weblog: LifeStreams as an attention aggregator
There's a lot of talk around at the moment about lifestreams, chronological behaviours, and new navigation and aggregation tropes. It's something to do with twitter, and jaiku, and all of these new microblogging/presence services that are getting so much attention.
I tried to comment on Jeremy Keith's site - but the sensible man has comments turned off, so I'll just hope this gets picked up by Technorati.
There's a very interesting book - The Aesthetics of Computing by David Gelernter, which covers the idea of using chronological streams to organise files in an OS, partly because it's a much more natural, human way of remembering information. This is kind of how I feel about tagging as an organisational structure; it's not elegant, or concise, but it's very useful for 'fuzzy recall' - finding things that were a bit like the other thing, that might have been about the time that you were doing that other thing there.
As search and indexing of files within systems and the web becomes more comprehensive and useful, there's little reason to keep the old directory strucure/file system metaphors visible at the consumer interface level. Lets make something that works the way people think, instead.