Disqus the popular comment system, today integrates with "Google accounts", in addition to Twitter and Facebook.
Disqus says that nearly 13% of users choose to login through Twitter or Facebook when participating in Disqus communities. That's why we've now introduced another recognizable choice "Google accounts."
"Millions upon millions of people are already logged into their Google accounts, and now they can easily use those accounts to jump into discussions all over the web.
We use Google's OpenID + OAuth support to securely authenticate users without sharing any passwords. If you already have a Disqus profile, you can also connect your Google account in order to link to your Google page and use your picture," stated Disqus.