Big Ideas, what are they all about?

So what makes a big idea?
For most people the first thing that comes to mind is a product, the latest whizzy gadget. You press a button, it goes meep, how did I ever survive without one?
But there are also a lot of ideas out there that help companies save money, work better or change the way they do things. These are great as well. I am going to be looking at both and if you think of any, I would love to hear from you.