I love inner tubes, because for me they are so much more than a component of a tire. It is a round tubular balloon made from a hardy material, like synthetic rubber. They are generally inserted into a tire and inflated to maintain air pressure.
You will often find these in car tires or even bicycle tires and in all different sizes and sometimes colors. What is great about these is that they can be used for many different purposes, some much more fun than practical.
One of my favorite uses is called, tubing. Tubing is a recreational sport that involves riding one on water. I personally have years of experience doing this. You simply inflate it and take off to a local river or creek (something with a current) with a group of your best buddies, some beer and a boom box. You tie all yours together and sit inside the giant donut shaped floating device and float down the river. It is a very fun activity guaranteed to leave you sunburned and tired, but fully relaxed.
Another excellent use for these is snow sledding or hill sliding. Instead of using a heavy traditional sled that can be a hassle to carry around, you can carry lightweight inner tubes and slide on down snowy hillsides. The slick texture of it provides the ability to travel at great speeds. Which is fun, because it adds an element of danger. You can also ride yours down dry grassy steep hills and get a similar effect with all the pesky cold snow. So, get yourself one. I did, and it changed my world for the better!