Who needs a bike pump when your tyres don't even need air? With Britek's Energy Return Wheels, you'll never get a flat tyre and according to the manufacturer, it's better than conventional tyres when it comes to performance. Among the features listed for the Energy Return Wheel include more efficiency, high speed, in-wheel suspension, light weight, durable, puncture proof, improved rolling resistance, superior acceleration, and hill-climbing advantage. However, one big disadvantage over normal tyres is the price. A set of these airless tyres will cost you at least $625. Also, it's probably not a good idea to take these on a muddy trail at the moment.
Check out NASA's and METL's on punctureless tires.