Why doesn't ftp_connect work in my php script?

If you are trying to ftp to another server from your web server, one thing to be aware of is that some hosts (bluehost.com is one I know) block outbound ports. This means that a script running on your website that needs to ftp a file to another server will not work.

In the case of bluehost, you need to get a dedicated IP address, which will cost you a little extra, but allow the php ftp functions to work.