If anyone has an invite, send it my way! xD; I'd love to give this a go.
NRK (Norwegian news) posted a little workaround on how to trick the system into letting you in, worth giving a go?
If you're already on Google+, make a photo album and share it with someone who isn't on Google+. This will send an e-mail with a link to the album, and on the album page there'll be a link to sign up for Google+.
They might have fixed this workaround by now, but it's worth trying out!
My gmail is tofumctwiss @ gmail . com 8D