Initally I was simply going to use a force resistive sensor, a couple cheap comparator chips and run the on/off output of the comparator into a 555 trigger to send out a burst of flashing. The plan was to calibrate the sensor to trigger only during heavy G loading (ex. Foot contacting the ground) to keep the flashing from constantly triggering when the person was simply standing still.
Due to the cost of FSR sensors, and the bulky size of my homemade ones I had to scrap the idea. I needed a solution that would come in under $30 and work reliably (I also tried pedometer circuit hacking...but was very unsatisfied with the results). Due to my budget and time constraints using a simple one time programmable PIC was also out of the equation (could not find a cheap reliable sensor for flash triggering without using a FSR).
Final solution, let someone else do the hard work and simply hack up a cheap pair of kids flashing shoes to work with my larger design! This would be inexpensive, very reliable, durable, and would not eat up a bunch of my time. Prefect!