Once you setup Google Voice, the following message will be saved in your Inbox.
Welcome to Google Voice. Google Voice gives you a single phone number that rings all of your phones, saves your voicemail online, and transcribes your voicemail to text. Other cool features include the ability to listen in on messages while they’re being left, block unwanted callers, and make cheap international calls. We hope you enjoy using Google Voice.
What is not mentioned is that fact that you can get free calls with Google Voice so be sure to sign up while vanity numbers are still available.