Daemon

Hello, I'm wondering if it's possible to create a daemon with PHP. I want to set up a script to run in the background and watch a folder. When there's any change to it, I want the script to establish a connection with an ftp site and upload the file. So my questions are: 1. Are daemons even possible with PHP? 2. How can I detect changes to local files? Thanks for any help! Brian Rak P.S. I'll share my program with anyone who likes if I can get it put together!