So, there has been some concern that Google has removed the ability to make voice calls from inside hangouts. I’ve found that the ability to do that still exists, if you know where to look.
Create a persistent hangout. Go to your Google+ page, create an event in the far future (12/31/2020), make it online only and then visit the hangout that it creates.
Take the hangout and shorten it using a service like bit.ly. Bit.ly works nicely because you can customize the name of the url. Be careful though since once the link is shared, you can no longer change the name and it will always point the supplied URL.
Go to the shortened URL and join your new hangout.
Click the invite people icon. Notice that you can now +Add telephone. Once you add a telephone number, Google will call them and they will join the hangout.
What is cool about this is that you can now have mixed hangout conversations with people in video calls and just pure audio calls. This will be really nice when most people are in an office but you have that one person who can only connect via phone. No more forcing everyone into a conference call…