[shorbaji]

Reminds me of Paul Graham's observation:

"Twitter is important because it's a new protocol. Fundamentally it's a messaging protocol where you don't specify the recipients. It's really more of a discovery than an invention; that square was always there in the periodic table of protocols, but no one had quite hit it squarely."

http://ycombinator.com/rfs3.html

[Symmetry]

Its not really a new discovery, the very first instant messaging system was half publish/subscribe: http://en.wikipedia.org/wiki/Zephyr_(protocol)

[efsavage]

NNTP?