Common Voices, a provider of IP voicemail systems, yesterday officially launched an enhanced voicemail service for Android G1 phones on the T-Mobile network.

The free service, called NowMessage.com, allows users to receive voicemail messages as email sent to their Google Gmail accounts. The email displays the name and phone number of the caller in the subject line and attaches the voicemail message as either a .WAV or MP3 file to which the subscriber can listen directly on his G1 handset. Subscribers can also be notified of all calls missed when the phone is powered off or out of service range.

And since NowMessage.com sends messages to the subscriber’s Gmail account, his voicemail inbox is never full and messages are protected forever. He can even forward, archive, or reply to a message just as he would to an email. As an added bonus, the subscriber “does not have to call in and use his voice minutes to retrieve his messages,” says Don Picard, chief strategy officer at Boston-based Common Voices.

“Why should voicemail be treated or arrive any differently than email?” he asks. “People who have smartphones [like the G1] are already at the place where they’re managing all their email with their phone, so it’s just natural to include voicemail.”

It’s those smartphone users—both consumer and business clients—who are the targets for this service, according to Picard. And it’s been that way since Common Voices first launched the service in beta testing almost a year ago.

Following the beta testing, it released its first application, for most BlackBerry phones, in October.  The service worked so well and attracted so many subscribers that the company quickly began getting requests from users of other phones and networks.

“We had a lot of requests for an Android platform,” Picard recalls. So, in December, Common Voices launched the G1 service in beta.  Since yesterday’s official launch for the G1, “we’ve been getting tons and tons of sign-ups already,” he says. “We expect Android to become a substantial portion of our subscriber population.”

And though the NowMessage.com service does not currently use speech-to-text capabilities to convert voice messages, that is something that Picard and others at Common Voices are interested in pursuing.

“Speech-to-text is a commonly requested feature to associate text to audio,” Picard says. “Sometimes you can’t listen to a voice message, or it’s just easier to quickly read text rather than listen to a message.”

The NowMessage.com service works with any email account, and currently supports the following carriers: AT&T, Cricket Wireless, MetroPCS, T-Mobile, US Cellular, and Verizon Wireless. New T-Mobile G1 users can sign up in seconds by visiting www.NowMessage.com.