Droppy is an utility that will help you to drag and drop files or folders between spaces or fullscreen apps. It's very easy to use.
Simply click on the app's icon in the status bar and Droppy will be ready to take your file, than you just drag the file to it.
You will have the ability to navigate through spaces, having the mouse free. This is very useful and comfortable.
Droppy supports any filetype, and works with any application, for example, may want to drop an attachment in Mail, an image in Word, or a file in Xcode.
Also, when you use Droppy with finder, you can choose to copy, move, or create an alias of your file's very own as you normally would with your Mac.