I understand that XMPP protocol allows connections from multiple clients to the same account. What I'd love, is to be able to access my rather significant IM account list from multiple devices at the same time (Home PC, Work PC, and Smartphone). Google-Talk & Facebook Chat are OK with this. But Yahoo!, MSN, etc. only allow single connection.
I'd love to find out if there is a site that combines all those protocols/accounts on the back-end side and exposes them via a single XMPP or other multi-account system?