My wife religiously takes her stash of these cloth-like bags that supermarkets were all hockin us with a year or so ago. She loads them in the ruck and goes off to do shopping. When she gets there she leaves the bags in the truck (she forgets to take em ad says "Screw it Im ot going back out to the damn parking lot" when she checks out.
Plastic bags around here have been converted to te degradeable soy oil plastic so its really biodegradable. (Its chemical half life is less than a month). The only drawback is that these bags MUST be recycled soon, since keeping them around and using them for . like, car trash bags will only demo how degradable they are. They oxidize into leedle chunks. A kid did a science fair project on bioplastic bags and the newspapers did a whole feature on the process so many of us are now clued into an entirely new branch of container
"Eco-feel -good- about- yourself-plastic bags"
Ive used mine as garden mulch , and we buried a dead chicken in one.