google-voiceGoogle Voice is rolling out today as a service that lets people use a single phone number that can be reached through multiple avenues.

Based on the Grand Central technology that Google acquired in 2007, the Google Voice application is rolling out on the Android and BlackBerry platforms. Google Voice users can get their own phone number to hand out to everyone but can choose to have calls to that number routed elsewhere.

It’s like call forwarding, where you can forward the call to your mobile, home, or work number as needed. Google Voice routes outbound calls through Google and then on to the person you’re calling, so it looks like you’re calling from your usual phone number. Since Google plays the broker for the call, it can solve the problem of friends not recognizing you as a caller when you’re calling from a number you don’t regularly use.

The BlackBerry and Android apps are being released in the morning. Users can listen to voice mails and read text messages. Google even transcribes the voice mails automatically. Users can also access call history or send text messages and call overseas at low rates. Previously, to place a call using Google Voice, you had to dial your own Google Voice number from your cell phone or use the Quick Call button online. With this new mobile app, you can make calls and send SMS messages with your Google Voice number directly from your mobile phone.

At some point, Google will also offer an iPhone version of Google Voice. Google Voice could compete with other voice services like Skype.

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