thanks for putting effort in a great plugin idea. I am using WordPress 3.4.2 on a selfhosted platform, an regardless which themes I use I get the following error when placing the shortcut code in a page:
Fatal error: Cannot redeclare class DropboxUploader in /homepages/15/d16736010/htdocs/BHT/wp-content/plugins/rad-dropbox-uploader/classes/dropbox.class.php on line 2
The form will be placed on the left upper corner of the screen.
Placing the same code in a post, the plugin just works great.