I now have a Google Apps account for my organization and I have a website where the users can register and change preferences of being in certain groups.
I have already created the groups in Google Apps and I found some information here that describes how to add members to groups (what I want to do) but I can't find out how to setup the Authorization.
I have an Ubuntu server running Wordpress (and the registration of users goes through PHP).
Can someone please tell me how to setup server to server authorization to Google Apps with PHP?