It’s been over a year since Google first previewed Google Voice, a Web-based service that basically enables users to set up a “virtual” phone number that can ring on a number of devices, handle voice mail and notifications, enable users to set up custom greetings and alerts, and much more. Now, Google has officially opened up Google Voice to the public—at least for users in the United States.

Among Google Voice’s top features is voicemail transcription, which enables users to receive a text version of voicemail messages left for them, produced using speech recognition technology. Like all speech recognition it’s not perfect—and sometimes produces amusing results—but is often a lot easier to manage (and cope with) than traditional audio voicemail. Google Voice also supports international calling, shared voicemail, call blocking and call screening, as well as personalized greetings.

Google says more than a million people are already using Google Voice; the company has also extended the service’s reach through a mobile application (although the iPhone version was famously barred by Apple, although a browser-based version is available). Google Voice also sports a number of useful features, such as the ability to port existing numbers into Google Voice, send SMS messages to email, and the ability to forward calls to different numbers based on the calling number.

There’s still no word on when (or if) Google plans to expand Google Voice to international markets.