Get some 14 passport size photos. Call a friend and show her the faces in seven photos. After that mix all the photos and then ask your friend to identify the seven photos she had seen. In most cases, you will find that your friend can pick up the correct photos, even though you had not asked her earlier to memorise the faces. You can repeat this experiment with a lot of other things like playing cards, picture postcards, etc.
Making a Musical Instrument
Take a cardboard box and on top of it you draw an oval shape. Then using scissors or knife, cut it off, so as to make a hole. Then on both ends of the box adjacent to the hole place two wooden wedges.
Now stretch rubber bands of different widths around the box. Now you have a toy stringed musical instrument.