Already back then Google announced that it would soon also come to websites. Well, soon turned out to be just about three months.
And with my @interpotential.com Google Apps account, I cannot create a Google profile. Oops. When I then logged in with one of my @gmail.com Google Accounts I could +1 a likealot, and a search on www.google.com also showed me the (rather ugly) PlusOne icons.
Anyway, if you do have a Google account which is not connected to Google Apps account you will be able to PlusOne more and more web content as site administrators and web developers implement the PlusOne button. But my personal guess is that it will never reach the popularity of the Facebook Like button.
Then again, I might be wrong ;)