Dare Obasanjo made a provocative point yesterday in a post titled "Open Source is Dead". His premise? That services like Twitter (and Flickr, and other "Web 2.0" things) create vendor lock-in differently - it's the community that matters most. So what if I have the source for a Twitter clone: can I create a community around my open alternative that somehow grabs people from Twitter? It's an interesting essay, and rather than try to summarize it, I'll recommend that you head on over there and read it.