The Dropbox plugin is still experimental, and shall be used to access a dropbox account via their API. To use it, you must first register as Dropbox developer to get your API Key. This is typically a driver with wich you create a Repository Template, leaving the users credential empty and filling only your API Key info : that way, the users are able to access their own DropBox account without the administrator having to know their credentials, but using a shared API Key. See the documentation about the Repository Templates.

Pear::Http_OAuth package must also be installed on your server in order to make the connection.