Concept: Change Detector
So my design was to alert you that you have change in your pocket. I was able to use a pair of shorts that had baggy pockets. I was able to store the arduino and power in the lower side pockets, and then run the wires into my pocket. Getting these connectors to not touch in everyday use was hard, but I was able to make it mostly successful by placing them at different elevations. In this case though, it often took multiple coins to trigger the detector. I then placed an LED in the lower pocket that lit up when the coin completed the circuit.
My circuit is much like the button circuit and the button code, except some of the pins are changed in the code and the wires are adjusted to allow for enough room. I used aluminum foil on the ends of the wires to make the connections in my pocket.