Lifestreams was invented by EricFreeman and DavidGelernter in the mid-1990s as a network-centric replacement for the desktop metaphor. The original dissertation is available at http://www.cs.yale.edu/homes/freeman/lifestreams.html.
Quoting from the Yale page:
A lifestream is a time-ordered stream of documents that functions as a diary of your electronic life; every document you create and every document other people send you is stored in your lifestream. The tail of your stream contains documents from the past (starting with your electronic birth certificate). Moving away from the tail and toward the present, your stream contains more recent documents - papers in progress or new electronic mail; other documents (pictures, correspondence, bills, movies, voice mail, software) are stored in between. Moving beyond the present and into the future, the stream contains documents you will need: reminders, calendar items, to-do lists.
You manage your lifestream through a small number of powerful operators that allow you to transparently store information, organize information on demand, filter and monitor incoming information, create reminders and calendar items in an integrated fashion, and "compress" large numbers of documents into overviews or executive summaries.
Also of interest:
Congratulations on inventing the most grandiose name possible for an Inbox. --HorselessCarriageThinking
Apparently, the name Lifestream was also in FinalFantasySeven?, and when this got on ReddIt? there were jokes about that.
So it's like Twitter?