Drop.io is a “simple private file sharing” site. When you go to the address, a personal web page address is generated for you….no sign-up required. (Although you will be setting a administrator password for the site.) You are allowed some simple appearance settings too.
An e-mail address is available for your Drop.io page so that you can send files that way too. Students can use this to create collaborative collections, and it can also be used as a dropbox for teachers to access student work paperlessly. There’s an upgradable version, but you can do all of the above for free.