Right now you can only create a single-file field on item types. It would be great if it was possible to create a folder field.
When you create an item you would then be able to select a folder in the file archive and a list of files in that folder would be rendered in a template loop.
If we could also provide a file search pattern on the field settings to limit the list of files to be rendered (only images, excel spreadsheets starting with "2013-" etc.) that would be awesome :)