Don’t throw away that old 4GB flash drive — it’s your best security tool

I have a bunch of old phones lying around in my drawer. Out of the lot, I’ve turned one into a security camera with a free app that gives me an extra set of eyes in places I want. I’ve converted another phone into a high-quality dash cam, which gives me the best features of dedicated hardware for practically free. Aside from a bunch of old phones, I have a bag full of old USB flash drives, out of which most are still in working condition.