Shopping Bags

I have so many plastic shopping bags. I recycle them. I also bought the reusable kind, but I often forget them in the car or at home, making it so I have more plastic bags. My mom put bags over my dad's feet so he could walk out into the rain and not get mud on his shoes when he went into the backyard. (Yes, he has rain boots, but this was faster). Ingenious, I say. What do you do with them?