Universal Inbox/Universal Outbox

FriendFeed was a real-time feed aggregator that consolidated updates from social media and social networking websites, social bookmarking websites, blogs and microblogging updates, as well as any type of RSS/Atom feed. It was created by Bret Taylor, Jim Norris, Paul Buchheit and Sanjeev Singh.

Here's a nice screenshot of someone's home-page showing updates from multiple users.

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