Originally, as GrandCentral, the service gave users a single number that, when called, would ring their home phone, work phone or cellphones, or a combination of phones. Re-envisioned by Google, it adds to this call recording, automated voicemail transcripts that can be viewed online, SMS messaging, conference call support and a means of forwarding problem callers to a “this number has been disconnected” message. Beyond these options, Google Voice offers a means of placing calls within the states for free. And international calls aren’t all that more expensive, two cents a minute to France or China.

A compelling set of features and one that will undoubtedly make Google Voice a formidable rival to Skype. Whether the service is disruptive enough to cause trouble for traditional telecoms remains to be seen. Certainly, reliability and call quality are potential issues. That said, there can be little doubt that the telephone companies are looking askance at the service today.