When it switched Google Hangouts from Google talk, we missed
the ability to make call from Google accounts. Earlier this week Google
announced its back, you can make call from hangouts and its better than before.
It lets you place calls from within Gmail, Google+, and the Hangouts extension
for Chrome and the price of calling to the US and Canada are now free from all the countries where Hangouts calling is available. Also international rates remain
low.
Google announced they had improved desktop calling
experience in a number of ways like add multiple phone numbers and video
participants to the same call; and you can play sound effects (like applause or
laughter) with the Google Effects app
See more info at Official Gmail Blog