Click on the "Email Me" link in the sidebar and send me the email address you'd like the invitation sent to. I will not retain your address or use it for any other purpose than to send you the invitation.
As you may have read, Google+ isn't like Facebook or Twitter. I would compare it more with Friendfeed, if you're familiar with that site.
Once you've joined Google+, you might want to read this link. It's a "how-to" guide for the site.
Would you like an even easier alternative? The first 150 people clicking this link can get an invitation.
https://plus.google.com/_/notifications/ngemlink?path=%2F%3Fgpinv%3DJif0A0QlOy4%3AI7jqa81J-fc
