1. Synchronize Birthdays People like to celebrate there birthdays with friends on Social Networking Sites, but there is no option of Birthdays on +Google+ . So, I suggest to Synchronize People who are in your circles and they also have you in there circles, birthdays automatic synchronize to Calendars.
2. Tasks See this video- http://goo.gl/LkWZR to know more about how can you use Google Tasks. This can be used as Facebook events We can use it to schedule our #Hangouts and invite people before starting. The people who are interested to join, can accept the invite.