Would the internal combustion engine be an example?
It seems to be fast becoming a relic of the past as we live in a world of increasing pollution and decreasing oil supplies but we cling to it as if it is the only viable form of powering our transport system and we are perhaps missing the oppurtunities to develop sustainable alternatives for the future.

Our lives our roads and our cities and towns are all designed for the car. For many people, even getting to work by an alternative method is unthinkable. Unless we can let go of the car or find a good alternative power source, we will suffer much pain when change is forced upon us.