Grocery bags
I just purchased a set of large reusable washable (nylon) grocery bags that open wide and easily clip to the sides of a grocery cart to keep them open while you shop. 2 bags fill the cart and you can fill them while you shop and the bagger refills them as you check out. I like these much better than the little cotton bags because they open so wide for filling and unloading and they have wide straps to carry them upstairs or from the car into the house. Much better than trying to carry multiple little bags. Bet the inventor is making lots of money.

i often have to carry 4-5 of the regular bags, which can get pretty heavy to make it one trip!
I feel much better not having so many little plastic bags to throw away into landfills. Also, I am using reuseable "green" bags to store produce in the frig and on the counter--they absorb ethylene gas and definitely help the produce stay fresher longer.