On PHPMaster.com today there's a quick tutorial showing you how to use SSH and SFTP from inside your PHP applications (requiring the ssh2 package).

In today’s world with so many third-party integrations and content-sharing, it’s important to understand and make use of protocols like SCP and SFTP. PHP’s SSH2 extension, a wrapper for libssh2 which implements the SSH2 protocol, provides several functions you can use to securely transfer files.

Sample code is included showing how to make a SSH request to a remote server, define the key files to use and execute a remote command (like scp). They also mention the use of wrapper functions like mkdir that also work with SSH/SFTP connections. The post finishes up with an example class or two you can use to wrap your connection handling and make it a bit more OOP-friendly.