IN 1991 a Yale professor David Gelernter envisioned a lot of what we now do on the Internet. Future computing, he thinks, may be organized around a concept called "lifestreams."
A lifestream is a way of organizing digital objects - photos, emails, documents, Web links, music - in a time ordered series. A timeline, in essence, that extends into the past but also the future (with appointments, to-do lists, etc.). Facebook, with its "wall" constantly updated with postings by you and your friends, is a lifestream. Twitter's feed is a lifestream. "Chatter," developed by Salesforce.com for internal use by client companies, is a lifestream.