When using a non-standard port (> 1056) you gain some "security through obscurity". The port is not associated with an FTP server so it is not obvious what protocol to use. This way you do not broadcast the presence of your server to every passing scanner. Automated scripts usually look for the easy targets.
To connect, you need to supply the port, protocol, user name and password. A real FTP client works better than a browser.
Now, some words from my paranoid side. You should have some idea of the possible dangers so you can secure your setup. I admit to being somewhat paranoid, because I know "they" are after me!
Concerns about having a public
server go beyond people copying your files. Once in, a visitor with malicious intent can take control over the box and use it for illegal purposes. He/she may install keyloggers to sniff out account numbers, user names and passwords. If the RIAA gets wind of a server with mp3's available, legal teams get dispatched.
Of course, any computer can be compromised. There are probably thousands of boxes which have been hijacked by e-mail viruses or nefarious web sites. They are connected in botnets that serve up spam and perform DOS attacks. That's the Wild, Wild Web.