Google's new Gmail phone-calling service presents a challenge to Skype, as well as Gmail's email competitors. Google has been making aggressive plays

Google is rolling out a service that makes phone calls through Gmail. Calls to the United States and Canada will be free through at least January 2011, with international calls ranging between 2 cents and nearly $5 a minute. That presents a challenge not only to Google’s email competitors, but also Skype.

“We’re rolling out this feature to U.S. based Gmail users over the next few days, so you’ll be ready to get started once ‘Call Phones’ shows up in your chat list,” Robin Schriebman, a Google software engineer, wrote in an Aug. 25 posting on the Official Gmail Blog. “If you’re using Google Apps for your school or business, then you won’t see it quite yet. We’re working on making this available more broadly—so stay tuned.”
Once the feature is active, clicking “Call Phone” on Gmail’s chart list will open a window with a virtual keypad. From there, users can either enter a number or a contact’s name

“If you have a Google Voice phone number, calls made from Gmail will display this number as the outbound caller ID,” Schriebman wrote. “And if you decide to, you can receive calls made to this number right inside Gmail.”

Google’s other recent improvements to Gmail include Google Calendar Sync that supports Outlook 2010, an updated and streamlined layout, and additions to Gmail Contacts such as keyboard shortcuts and custom labels. Apps Search, available through Google’s Gmail Labs, allows users to sift through Google Docs and Google Sites.

Gmail’s rapid feature-adding could be a symptom of Google’s rising competition with Yahoo and Microsoft for email users. Although Gmail has managed to build substantial business off its sizable inbox and rapid-search features, its rivals have been working to level the playing field: on May 18, for example, Microsoft announced updates to Windows Live Hotmail that included clutter-elimination and security tools.

Google has also been additional plays in the VoIP market, including its May 18 agreement to purchase Global IP Solutions (GIPS), which makes software for processing high-definition audio and video over the Web, for $68.2 million. Along with phone-calling from Gmail, Google Voice and its 2009 acquisition of Gizmo5, that puts Google in a stronger position to compete against Skype and its 400 million users.