12 weeks under field trial and now its open to everyone. You dont need an invitation just to signup for google plus just go to http://google.com/+ and sign up.
Google+ also releases 9 new features. one of the most exciting feature is the HANGOUT ON AIR.
you can now broadcast your hangout sessions. you 9 persons can still join your hangout but everyone can watch your hangouts..
also Google Hangouts is now available on android phones with front facing cameras. now you can hangout anytime, anywhere.
to know more about Google+ exciting new feature read http://googleblog.blogspot.com/2011/09/google-92-93-94-95-96-97-98-99-100.html ..
dont forget to add my friend pareng hilton on your google plus circles.. https://plus.google.com/110794977179725605444 and soon Katechpuan itself.