We have Google plus invites for first people to comment on our related blog post: blog.attollos.com enjoy and good luck!
I was careful with the forum which I put this in / thought some people might like to try out google plus. I'll remove if you feel it is not relevant.
You have to write something in your stream then go to share with and add email addresses. I'm not even sure if there is a 5 person invite limit!
I am not sure it matters at this point. I tried to invite a friend of mine and when he went to get in on it, it said that it was at over-capacity and that they are working out "kinks". Then it asks you to leave your name and email and they will get back to you lol