A small but very cool news is that if you have a google hangout going from your phone with your best friend, spouse or anyone really, if you have their number and google account you can now chose for each message you reply if you want to send it as a traditional hangout message or as a text (SMS) message.
It is a small but cool feature and hangouts just got even better!
This means that if you can not reach someone using hangout you can immediately resent using SMS instead and so on. It’s just great.