A full example, that should work.

gistfile1.js

var gotPicture = function(path) {
$('#previewPic').attr('src', path); /*optional */
		var params = {foo: 'bar'};

		var cookie = localStorage.getItem("Cookie");
		if(cookie) {
			params['__cookie'] = cookie;

		}

window.plugins.fileUploader.uploadByUri('http://example.com/upload', path, params, 'photo', 'image.jpg', 'image/jpeg', 
			function(result) {
				console.log('Done: ' + result);
			}, 
			function(result) {
			console.log("error: " + result);
			}, 
			function(loaded, total) {
				var percent = 100 / total * loaded;
				console.log('uploaded  ' + percent);
				
			}
		);

	}

}

var getPhoto = function() {
navigator.camera.getPicture(gotPicture, null, {destinationType: Camera.DestinationType.FILE_URI, sourceType: navigator.camera.PictureSourceType.PHOTOLIBRARY} );
}