If you've ever wanted to quickly and easily connect your PHP script over to a SAP server to authenticate a user but weren't sure quite how, you'll be happy to see that you can use the PEAR::Auth package to make the request - with a little help.
PEAR::Auth is a package that allows you to abstract the user authentication from the main part of your application and not worry about it. What is good about the package is that it comes with different "containers" that allows you to authenticate users against different storages.
So I played around with creating an SAP container that allows you to check users against your company's SAP system and for example build a section of your Internet (or Extranet) page that is only accessible for people and partners that exist as users in the SAP system.
There's an extension to PHP you'll need to get and install, but with that in place, it's as simple as setting the authentication type to "SAP" and giving it the hostname to connect to. He also includes some sample scripts to get you started, including the Auth_Container_SAP class that makes the magic happen.