If you do insist opening an FTP server to the internet, the easiest access method is via a dedicated FTP client. A great free one for OS X is
Cyberduck (they have a beta that is 10.6 compatible), while Windows users can download the free
FileZilla.
You can also access an FTP server via web browser or Finder, but I almost always prefer the ease of configuring a dedicated client. Usually all you need to provide is an IP address (or domain name), username & password.
