Can you do a group Google chat with Messages? How do you do a group Google chat (Hangouts) with iOS Messages? Specifically I would like to do a group chat via iOS Messages with multiple people who use Google Hangouts either where they initiate the group chat or I do.

Thanks all for any ideas or suggestions!
You can do a group conversation in Messages, but there's no way to automatically have it set up based on a group from Hangouts.

To start a group conversation in Messages for iOS, tap on the paper/pencil icon at the upper left of the threads list, then simply enter as many contact names or phone numbers as you like. When you send a message, it will create the group automatically.