so I just came up with a new gadget. I live in costa rica where you can only buy coconuts, bananas and surf boards

Im rather proud of this one (thats why Im sharing it with you)
being a pyromaniac myself, I love things that go bang, poof or woosh. any way max get to the point, I have made a gizmo that will make a loud bang with sparks and smoke, its super cheap to make, and its oppertunities are limitless. use it like a finger flasher, but without expensive flash cotton.
what you do is go to a novelty shop (we even have these in costa rica) and buy yourself an exploding pen, walet, chewing gum etc. and remove the exploding gizmo, litle metal thing that uses toy gun caps to make a bang. now you can attach a small rubber band to put around your middle finger, load it and conceal it when your ready set it off. I like doing it in an elavator and pretending to get a big fat shock.
try it, and if you have any ideas to improve it or any bad points please let me know.