The new "Voice Calls from Gmail" service allows you to call any phone line from within Google's (Nasdaq: GOOG) Gmail application. It's free to the U.S. and Canada, and as little as $0.02 per minute for international calls. You can also receive incoming calls if you have a free Google Voice account.

Fool analyst Rex Moore says the value of this new service to consumers is uncertain. The ability to avoid major telecoms like AT&T (NYSE: T), Verizon (NYSE: VZ), and Sprint Nextel (NYSE: S) has been available for many years through computer-to-computer calling, or services like Skype. But nothing has seriously challenged the big players.

As New York Times tech reviewer David Pogue points out, the Gmail phone service gets us closer to free phone-to-phone calls. What if, Pogue says, Google could get an approved app for its Android devices or Apple's (Nasdaq: AAPL) iPhones? The competitive pressures from Apple's and Google's telecom partners seem to make this unlikely.

Bottom line: The value of this new service really depends entirely on how comfortable you are with all the technology, and some of the hoops you'd have to jump through. Still, Google is in an envious position of developing all this (mostly free) technology to build advertising around, while disrupting other industries.

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