Make a drawing… get a drawing. This quaint little site will give you a blank canvas to leave your mark. You’ll then receive a drawing from someone else doing the same.
If making a drawing isn’t you thing, give file swap a try (from the same folks as sketch swap). It’s works the same way, only you don’t need to draw, just drop in a file (image/sound/video/document/whatever) and you’ll get one back.