The only thing that I think of is by going to http://webdisk.username.heliohost.org but you would need to login using your FTP account. I'm not sure creating a guest FTP account would work or not but even if it works, the visitor might have access to your personal files. EDIT: I haven't tried this yet but creating an FTP account for your clients might work since you can have a specific directory for them to access. This way, they can't access your personal files.