$('.uploader').fileupload(
{
    dropZone: $('.upload-drop-zone'),
    dataType: 'json',
    url: uploadUrl,
    progress: function (e, data)
    {
        // data.files is an array of several files, so I don't know which file this progress event is for???

        var progress = parseInt(data.loaded / data.total * 100, 10);
    }
});


// Later on I use this to start the upload of files
$('.uploader').fileupload('send', { files: myArrayOfFiles });