PHP - How to implement user registrationg using OpenID
<p>I would like to use OpenId on my site to allow user registration using Google, Twitter, Facebook... i have seen a lot of libraries to implement that in PHP but i have some doubts; especcially my site request some info when a user sign up:</p>

<p>1-)id generated by the system. When an user sign up with OpenId EVERY service generate an id and how is it?
2-)username. What about it i need to ask the user about?
3-)Password. i don't think that gogole give me the password of an account, i need to ask the user for it?
4_)email i think there aren't problems with it</p>

<p>Another thing: i noticed that a lot of sites that use OpenID or similar write "login/sign in" and not "sign up", with OpenID i can setup a sign up or only a sign in that works as long the user is connected to the service?</p>
