With the snippet an upload button for uploading multiple files with progress counter is generated. Works well in FF3.6+, Safari4+, Chrome and falls back to hidden iframe based upload in other browsers, providing good user experience everywhere.
All uploaded files and generated thumbnails are given random filenames to avoid hotlinking uploaded not published files. Automatic thumbnail generation for uploaded jpeg, png and gif files. Other uploaded files will get a generic icon the file extension.
With two FormIt hooks the upload queue could be pre filled from a FormIt field value and be saved into a FormIt field value. With a third FormIt hook the uploaded files could be attached to the FormIt mails.