How do I implement gmail login?

How do I implement site authentication using gmail, yahoo or facebook IDs (not OpenID login)?

PS: Using PHP.

From stackoverflow

• Google offers two APIs for login: http://code.google.com/apis/accounts/docs/AuthSub.html http://code.google.com/apis/accounts/docs/OAuth.html

  Yahoo also offers another one: http://developer.yahoo.com/auth/