I think space blankets are one of the most multi-sensory man-made pieces of plastic ever invented. I can't get over the fact that you can look through them - they are actually transparent. The noise made by shaking and scrunching space blankets makes them a worthy musical instrument in their own right.
They are light so little children can run around with them.
At some point the super-hero inside each of us makes an appearance and the space blanket becomes a cape...
Some children love tossing the space blanket into the air. On windy days I tie this to a pole or fence to stop it blowing away yet allowing the wind to catch it.
Space blankets are a useful additional to den building. Look at the posh house which can be made with a space blanket, a plastic poncho and some masking tape.
Naturally any Christmas shop will be given an extra sparkle through the use of a space blanket.