Yes, Twitter and Facebook -- and the blogosphere, Wikipedia, Second Life, World of Warcraft, ad infinitum.

Beyond these particulars, an abstract principle; as in Edward Barrett's sociomedia:

"[Terms like 'hypertext' and 'hypermedia'] make 'machine' predominate in one's thinking rather than the ultimate worth of using the machine. 'Sociomedia' calls attention to this ultimate value. 'Sociomedia' suggests that computer media exist for 'social' purposes: as means to objectify, exchange, and collaborate, invoke, comment upon, modify, and remember thoughts and ideas...."