Voice over Internet Protocol (VoIP) is a general term for a family of technologies that enable voice communications over the Internet (and corporate intranets). Strong double-digit growth has placed VoIP into everyday life for many millions of people. In the early days I used Packet8. Then a VoIP system was created by entrepreneurs Niklas Zennström, Janus Friis, and a group of software engineers based in Tallinn, Estonia. I happened to be in Tallinn as part of a Baltic cruise a couple of years ago and wondered why the cobbled streets of a nearly thousand-year old small town on the Baltic Sea was lined with brand new high-end sedans. Later I realized that Tallinn was a mini Silicon Valley and home to the development of Skype. Skype became my "phone" for both SMS messaging but especially for calling home from abroad for free. Skype was a game changer. Beginning last week another game changer has become my phone — Google Voice.
Like Skype, Google Voice is a free VoIP service in classic Google "beta" test status but I have already adopted it as my preferred service. While attending Demo in San Diego in September 2006, I became a beta tester for a VoIP service called Grand Central. The following year they were acquired by Google and after a quiet period of development, Grand Central was launched as Google Voice. Being a Grand Central beta tester got me an early Google Voice account.
The conversion was simple. I had not been using Grand Central much because there was no way to sync the contact list. With Google Voice you get instant sync with your Gmail contact list. When you start out you get a phone number for most any area code you want. The new number then becomes your only number. When someone calls it your cell phone, your office phone, you home phone, and a vacation home phone all ring. You answer and hear who is calling and press 1 to accept the call. Or for some people that you designate, the call goes straight to voicemail. For others only your cell phone rings. You can add your contacts to different groups and have each group be treated differently. You can "ListenIn" on voicemails as they are being recorded and then decide to enter a conversation. When you receive a voicemail you get an email containing a machine transcription of the message. It is not perfect but good enough that you can tell who it is and what the call is about. You can block callers, record conversations, or add them into an ongoing conference call. Up to four callers can be added to a free conference call. The history tab in Google Voice shows all of your inbound and outbound calls. Needless to say you can search through the history of all your calls to refresh your memory about a conversation you had a year ago. SMS messages and all of your calls have shared inboxes, trash, history, and spam folders just like gmail.
The feature I like the most is that you can install Gizmo — a free VoIP program that runs on your PC — and add your SIP number as one of your Google Voice phone numbers. When a call comes in a dialogue box pops up on your display. You click "answer" and then the call can be handled with a headset (I use a Plantronics noise-canceling model) which provides hands-free high quality audio for me and the caller. Another nice feature is that you can make a Google Voice call from your iPhone (or any mobile phone). All U.S. calls are free. A call to Norway is two cents per minute. With free conference calls and a boatload of other free features, Google Voice is going to put the heat on the telephony monopolists. It will also put pressure on eBay’s $2.5 billion acquisition of Skype for which they later took a $1.4 billion write-down.
The best way to reach me is still to send an email but now you can also leave a message for me at Google Voice.

• Google Voice (or is it Google Data?)