Well, long time ago I tried Weave (0.1 version) and I left behind in a second, but I don’t remembered why.
Today I was reading something about Ubiquity (I will blog about this awesome extension in a few days, when I have played with it), and suddenly: Weave. Why not give it another chance?
The answer could be: it’s full. Nobody can sign-up now. The server is crowded, so it’s slow, buggy… And yes, it is full and crowded. But you can create your own Weave’s server. And I did on my Dreamhost server (this how-to is focused in Dreamhost, but could be adapted).