You can hang so many different things on cords. Threading a cord through the handles of shopping bags and then securing the cord can help keep your groceries from sliding around as you drive. If you need a clothesline in a pinch, you can stretch a elastic cord (or multiple if you need a longer line) between two trees. Elastic cords also make great curtain rods.
Elastic cords also make good barriers. You can take a few cords and a length of fabric and create a baby gate to keep small children away from dangerous places. It's so easy to knock things off shelves that don't have barriers. Elastic cords can help hold all the items on your shelves in place so you don't have to worry about always knocking everything down. If you play a lot of sports, you know it can be hard to find a good place to store all your balls. Using a few pieces of wood and some cords, you can create your own ball cage like the ones they use in stores. You'll never have to worry about your balls rolling around the garage again.
Elastic cords are also great for various crafts. Braid a few cords together to create a stretchy friendship bracelet. You can use cords instead of twine in many projects to create a more colorful and quirky end result. You can spice up furniture with bungee cords in several ways. Weave a cord lattice between the legs of an end table to make it look more interesting. You can also wrap some cord around parts of your furniture that are scratched or chipped. It will make your furniture look quirky and rustic instead of banged up.
There are many other things you can do with these cords. The only limit to how you can use them is your own imagination.