Dang, Lady! You and I must be on the same wavelength lately! I've been wondering the same thing! I was just thinking yesterday that I feel like I'm already living in during a depression where nothing gets thrown away without careful consideration as to what other purpose it might fulfill.

I save the grocery bags from Walmart but only there because they're white and presently I use them in the bathrooms. Our bathrooms are white so it still looks nicer than having a brown plastic bag from other stores. I fold them all up nicely and put them in gallon ziplocks and stack the baggies neatly on a shelf.

I save bread ties because I use them in the garden. Toss them in a ziplock and put them in a drawer.

I save glass jars of all shapes and sizes. They come in handy for all kinds of things, especially homemade mixes and such and I don't have to use my canning jars.

I've started opening my canning jars carefully and saving the used lids...just in case. I've heard that some old timers used to do it and reuse them. I know you're not supposed to but if things ever get desperate, well, desperate times call for desperate measures.

I wash and reuse tinfoil if it's just a piece I used to temporarily cover something.

I'm sure I do more but that's all I can think of right now.