Goodyear has invented an airless tire that promises not to get ever get flat. There are spokes going out of the hub of the wheel, and it extrudes material that acts as your tire. It's based on how spiders weave their webs with silk. When your wheels run out of material, you simply reload the capsule. You can also pop in a different blend for cold weather or warm weather. It probably won't see the road until the late 2020s, but it's still pretty cool.