Twitter is the new MySpace
Twitter is rapidly becoming the same for me. Anthony Stevens wrote this morning about how the decision was like super-delegates choosing sides. Without getting too political I think the metaphor is apt only if you consider the demographics which tend to come down on either side of that particular decision. Chris Pirillo said it best that Twitter is "asynchronous IRC" - a raw feed. The loudest voices dominate my twitter window, and the noise is deafening. Finding a "new voice" is like a needle in a haystack.
FriendFeed is like Twitter with actual conversations. Someone marks an article from basically anywhere, and it forms a locus for comments on that particular topic. No more sifting through @s and "in reply to's" that don't even point to the same post anymore.
The second big advantage of FriendFeed is in the ability to widen or shrink the pipe you transmit and receive. By opting into services you control what you communicate, and with the hide function and rooms you have a dial to control the gain on the noise stream.
Third, FriendFeed is an amazing place for finding new voices. When a friend-of-a-friend comments on an article you can get a feel for their perspective as an introduction, rather than finding out where they had lunch. If you have something interesting to say it is easy to make your voice heard in context, something virtually impossible with Twitter.
Armchair pundit: the next great movement will be Seesmic + FriendFeed. Video is spectacularly expressive, and in some ways the barrier is actually lower than with written commentary. The main downside is the inability to skim... and on video especially people tend to ramble. I predict new cultural memes for mini-video brevity to fight the problem, followed eventually by software organization... FriendFeed for Seesmic.
In the meantime I'll keep my Twitter account because a lot of friends and colleagues use it, but there is no question in my mind which technology has the edge.

