We are gradually changing our wheels over to being fitted with tubeless tyres.
In simple terms it's a wheel fitted with a proper canvas re-inforced rubber tyre (similar to the ones fitted to your car) but, instead of having an inflatable inner tube, it has a high-density foam insert:
So why are we doing this? Because it gives you all of the advantages of a pnuematic tyre wheel with none of the hassles of keeping it blown up or dealing with punctures.
But don't confuse these wheels with the wheels on a lot of buggies. They are often foam wheels without proper tyres that, if fitted to a go-kart, would wear out very quickly and wouldn't run very well.
They also give you an improved ride as the tyre cushions the bumps.