Earlier this week Google opened their Google Voice service to all.
Google Voice offers a single phone number that can ring on all of a user’s phones, either all of the time or by a schedule that can be applied to each number. The service also has a voice mail box which can transcribe the message to text and send it to an email address or as SMS to a cell phone.
To use the service all you need is an Google account. Currently users will have to select a number supplied by Google Voice. Although this could change in the future.