Supply someone in Google+ with your email, but it seems like they're not accepting anymore for now :/
I have an Invite circle and just add emails into that and send a post to them. It seems to send an invite to their emails.
If anyone could be kind enough to send me an invite, it would be well appreciated. studangerous at gmail dot com Thx Edit/ someone was kind enoigh. Thx Tom. Got my Google+ thang going on now