OpenID vs. OAuth

What is really the difference between OpenID and oAuth? They look just the same to me.

PHP Tutorial for OpenId and OAuth

Is there a good tutorial for implementing OpenId and OAuth together in PHP? All of the OpenId tutorials I've seen on the official OpenId site haven't been as helpful or as simple as they could have been. I don't think I've seen any tutorials on using both of them together. (For OpenId, I'd want to be both a provider and a consumer.) If there are no tutorials for using them together, tutorials on implementing either one in PHP would also be helpful.

Do Facebook Oauth 2.0 Access Tokens Expire?

I am playing around with the Oauth 2.0 authorization in Facebook and was wondering if the access tokens Facebook passes out ever expire. If so, is there a way to request a long-life access token?

Facebook Oauth Logout

I have an application that integrates with Facebook using Oauth 2.

Zend_Gdata and OAuth

I successfully retrieved token key / secret after applying Google Hybrid Protocol (OpenID + OAuth).

Facebook authentication error - The operation couldn’t be completed

I have an option in my game for users to post an achievement to their wall. If they are logged in, i.e. their token is still active, it works fine. However, if they need to renew their token, the app exits and the Facebook authentication page loads for a second before returning to the app (they only need to click OK on the authentication page if they have actively logged out, otherwise it happens automatically).