For Google+ users, the www.google.com/profiles/me URL redirects to the user's Google+ profile. How can I use Google as my OpenID provider now?
If you mean you want to use your Google Account to login to sites using OpenID (like the Stack Exchange network) even if you don't have Google+ then you need to use the following URI:
If you are already signed in Google will recognise your account and perform the necessary actions. If you aren't already signed in to Google, you will be prompted to sign in before you can continue.