Google Voice is a an invite only US-only service by Google that provides additional benefits to phones and voice communication.
This includes voicemail transcriptions, notifications, a single phone number for all phones, custom greetings based on the caller ID, or the ability to share voicemails for all users who have created a Google Voice account and linked their existing phone number to it.
You get a single phone number linked to you and benefit from other features on top of that including free messaging, call blocking and recording, verifying callers before picking the phone up and selecting which phone should ring when throughout the day.
Google Voice for Google Chrome
Google Voice for Google Chrome is an extension that provides you with access to several Google Voice features directly in the web browser regardless of website.
The Google Voice extension displays for instance the number of unread messages of the Google Voice inbox, plays audio alerts when new messages arrive (with the option to turn that feature off) and offers quick access to recent messages with transcripts and voicemail playbacks.
The extension furthermore allows you to send free text messages, and to initiate calls right from the extension menu by typing a number or contact name.
Phone numbers on websites are made callable via Google Voice by clicking on them with the fallback option to highlight the phone number on the website instead in case it is not picked up correctly by the extension. The latter may happen if the format that it is displayed in is not recognized, or if Google Voice does not identify the full number.
Google Voice for Google Chrome can be downloaded from the Google Chrome Extension gallery.
Several of the features that might get annoying after some time, like audio notifications of new messages or the automatic modification of phone numbers to links can be turned off in the extension’s options.
Google notes that SMS are only available for accounts with a Google Number and not for voicemail-only accounts. Google Voice is currently only available in the United States.
Update: the extension has not been updated in three years. It still works, but no new features, bug fixes or improvements have found their way into the extension in that time.