Remember that balloon-like robot hand that could pick up everything even without fingers? Engineers in Canada are taking a similar approach in redesigning the wheels for rovers headed to other planets, using a beanbag-like form that would be able to tackle all kinds of terrain.
It's called the (and here I pause for a sigh) iRing, or iron ring. The idea driving it is similar to that robotic gripper: the beanbag tires yield around and in to the terrain, but the chainmail-like links of the tread still give the wheels traction. The iRing tires are able to traverse any manner of terrain effectively, and are even able to scale up surfaces that are taller than the wheel itself and help absorb shocks better than traditional tires.
Why just limit these sweet wheels to rovers? Just imagine a world where your ride is always smooth because your tires are changing to the terrain, not skipping along above it. Hell, or even cars that don't hurt you when they run you over, as the tires just mold right around you. The iRing won't accomplish that, exactly, though it could do wonders for rovers exploring a craggy moon or Martian desert.