Earlier this week, Google introduced a feature that lets you make VoIP phone calls to landlines and mobile phones from within your Gmail account (and iGoogle). The calling service, which is available to U.S. Gmail users, integrates with the Google Talk chat app that you can find on the left-hand sidebar in Gmail.com. Google’s “Call Phone” feature has so far made a splash, inspiring 1 million calls in its first day–even before all Gmail users received the notification that they could activate the feature. A favorable response is good news for Google, whose last opt-out Gmail feature, Google Buzz, only incited ire and demands to make it easier to disable Google Buzz. In addition to staying in consumers’ good graces, Google’s VoIP service in Google Talk is a potential moneymaker for the company. It’s currently free to make calls inside the U.S. and Canada; however, to make inexpensive international calls you must buy credit through Google Checkout. Google’s Gmail call feature is undoubtedly a dangling carrot that can boost Google’s formidable bottom line and reinforce some of its other services. If it’s heavily adopted, as we suspect its convenient placement in the in-box will warrant, the company’s dominance as a trusted, go-to brand will surely continue to grow. Watch our video above for a step-by-step tutorial on how to make calls from Gmail to get started.