Yes. Don't throw away over-ripe bananas: freeze them in their skins to use later in cakes or muffins. When you want to use them, simply peel, defrost at room temperature and then mash.
Yes, I freeze them with their skins off and then use them for milkshakes. Take them out then cut them up whilst frozen and chuck them in the blender with milk, yoghurt, icecream, honey - whatever you want the choice is yours Yummy!!