As I am a pump person we have found the blue plastic bit at the end of the syringe which hides the needle going into the insulin vial very useful for the Doc Who Tardis model made by my son. The plastic canula packaging have become eye parts on kids models at the local school where I work and the two(why 2 ?) booklets which I get with the canulas are recycled. Otherwise sharps in the sharp bin and the rest in the black bin. I used to enjoy making a great noise with the plastic syringes by holding my finger over the needle end and pulling the plunger out or squirting my sister with water in the summer. I suppose you could always fill the insulin vials up with coloured water and pretend to work in a chemist (I always liked Boots blue apothecary jars in the windows)