With its new converged messaging service announced today, Facebook took several more steps toward David Gelernter’s Lifestreams concept, first outlined in the mid- to late-1990s. See an old Yale web page on the topic, the newer Lifestream blog, and a 2009 interview with Gelernter. A lifestream is bascially a digital representation of your life — all the communications, documents, photos, blips, bleeps, and bits that come and go . . . arranged in chronological order as a never-ending river of searchable information. Google’s Gmail was the first popular application/service that hinted at the Lifestream ideal. Facebook — with its “seamless messaging,” “conversation history,” and “social inbox” — now moves further with the integration of email, text, IM, and attachments in never ending streams, accessible on any device.