What cool things can I do with this box of model rocket engines?

I recently re-discovered this box of model rocket engines in an ammo can in my garage.  They look to be in great condition.  I don't have any of my model rockets, or any parts to build them.  I'm really wondering if there is something else interesting I could do with these.  Also, they are at least 20 years old.  Prolly still good, right? :/

Picture of What cool things can I do with this box of model rocket engines?
Hot glue them onto hotwheels cars, hot glue part of a straw onto the bottom of the car and run fishing line through it. Hook em' up and let em' rip!