Hitting radiator with fingers and scrapping over with a metallic object (car-key). When amplify the quiet content, some interesting sound can be worked out. Recorded with a ultra cheap microphone unit of my mp3 player. Reduced noise.
A sound effect of me hitting my bed with my hand, made to sound like a mat hitting the floor. Or it could be used as a thud sound effect. Used in my short film "wake up" (yet to be uploaded).