iPod, GPS, credit card, microwave oven, bar code, light bulbs, telephone, - what do all these have in common?
They're amonst the list of 25 inventions that have changed our way of life, see: http://list25.com/25-inventions-that-changed-our-way-of-life/.
And to think that, for instance, when electricity was discovered people couldn't think of many uses for it!
This is a very interesting website which lists 25 best of all sorts of things. A proper time-waster but fascinating at the same time.