I heart disruptive services and technologies. Especially the kind that enable something obvious that consumers have been asking for but have been denied.
While this falls under the “few on the internet are likely to care” category the gtalk2voip service has added Yahoo! Messenger support. This (for now) open and free gateway allows Google Talk, MSN/Live Messenger, Yahoo! Messenger and SIP phone users to call one another for free.
At the moment it appears that 3rd Party Interop is the way forward. For the sake of QoS, etc I really hope the “right” companies will peer their gateways and open up access. From my perspective this is just a hack in the right direction. Albeit, one I intend to start using.