Web Service in PHP/XML

I started writting an install script that would talk to a PHP script on one server while being used on another. So you would have http://www.someserver.com/install.php --> http://www.homesever.com/install.php via CURL without the users knowledge. The script would pass certain variables and if one didnt jive then the install would stop and a message would be sent back. If everything was okay then the client would have the rest of the source ftp'd to the http://www.someserver.com server and the install would continue until everything was finished. I have done very little with CURL, I'm not sure if there are any tutorials or anything else that I could see to get some good examples of both ends of the process anyone know of any? Anyone know of a better way? I'm also looking into XML or Java on the authorization end but not sure yet. thanks. dan