Gmail currently provides free domestic calling for users in the US and Canada, directly in the Gmail interface. It uses the Google Video Chat plugin to allow voice calls to be made to regular phone numbers, and if you have a Google Voice account, integrates with that as well.
This feature used to be built right into the chat window:
As of the update for the new integrated version of Google Hangouts, I can't seem to find any button to place a phone call from within Gmail.
Furthermore, when I place a call from Google Voice and tell it to dial through Google Talk, the call doesn't go through.
Is there any way to use the new Hangouts while still having the phone call abilities?