There's really a need for IM interop. These fragmented islands stall the network effect (Metcalfe's law) that is needed to sustain and grow communities.

I guess the best thing for the current situatio would be a headless service that would connect to your IM identities, and buffer messages, from many different IM identities and protocols. You would then have intermittedly connected web or terminal or mobile apps as its clients. Does something like this exist?

It only support public channels at the moment, but we're planning to add user/user communication too.