Iminta has a cool thing going for it: you can put your followers in groups and specify which group sees what... I really like the idea of variable resolution for social feeds. Still in beta as of 3/16/08
The challenge for Friendfeed and the like is that while I really like all my services gathered in one place, I would rather that these would be centralized on my blog instead of a third party service. Yes you can cross post or add badges, but it's not rea