Is there a setting for the file-fieldtype or a third-party fieldtype that allows only to upload a file (and NOT browse existing ones).
The goal is that certain member groups are only supposed to add files.
Channel Files will probably do what you're looking to do. The "Limit Stored Files by Author" setting is probably what you're looking for, here's a screenshot of the fieldtype settings screen: http://www.devdemon.com/images/products/30/fieldtype.jpg
You can buy it here: http://devot-ee.com/add-ons/channel-files
I just remembered the Safecracker File fieldtype which perfectly fits the bill.
That said, I just read it has been removed in 2.7 ...
