The concept of starting up 'lean' is a hot potato right now, held tightly inside the silk-lined pockets of trendy startup guru-types. It's basic common sense wrapped up as a mystical gift from the wise. Admittedly, it is quite easy to get carried away with the ultimate vision for your startup, so delivering quickly in iterative chunks is a pretty smart idea. Doing things this way has the best chance of not bankrupting you as a result of developing something that nobody wants to use.
But it's not just small companies that do this. I was really interested to read a piece on BBC News about Barclays having a go (http://www.bbc.co.uk/news/business-17754810). Their idea is to physically stick a mini credit card on the back of your smartphone and use it with contact-less payment readers. This might seem a rather primitive thing to do, given that most smartphones are fairly technologically evolved beasts (except Windows Phone, of course). But it gives Barclays a low cost, quickly implementable product which they can use to test the demand for physically using phones to pay for stuff. By definition, this is a lean startup in the context of this new product. The other alternative would be for Barclays to build the full-on technological solution upfront: apps, security, chips blah blah. This would undoubtedly have a higher cost, which Barclays felt couldn't be justified as they are unsure of the demand.
Having worked for a bank, I never thought I'd be praising one's forward thinking approach to a technological problem. Seems even dinosaurs can evolve..