Would twitter exist if friendfeed came first?
Friendfeed enables a conversation around your travels through the online world. You can post pictures, videos and links on other sites or make a micro-comment on the site directly and everybody get to comment and have a conversation right now about that. Twitter on the otherhand is just comments thrown out there for all to see it has no threadding or real intergration with other sites and while people do have conversations there is a limited functionality to support this.
If friendfeed had been born first then I don't think that most people would even have heard of twitter if it had the current feature set. But twitter was there first by a long stretch and so it is ingrained in what people think of as a microblogging site and this brings with it a selection of sites that we see created that try to emulate this. Identi.ca and rejaw are a couple that I can think of that are filling a gap that should just not be there. I would be a lot happier of identi.ca was creating an opensource version of friendfeed that allowed federation and subscription across multiple servers.
I say drop twitter now and move to friendfeed until identi.ca can deliver a more open platform for online conversation (on-versation? because we need a really bad word play to call this type of site.).