Great little essay on the value of Design by Mike Monteiro:

This is the value of good design. We understand it in common objects like chairs, clothes, shoes, watches. But when it comes to web sites, we tend to think of it as a surface layer that can be applied at the end. But in truth, design is happening from day one.
Related to the problem of people treating design as a veneer is mobile ‘app’ design. Those who don’t understand application and UI design think it’s just glossy buttons and drop shadows (or now, frosted glass and buttonless Helvetica Light buttons).
It’s just a 99¢ app, it doesn’t require a lot of thought, right?
Wrong.