Why Smart Boards?

I desperately want to embrace and make use of the smart board in my classrooms, but only if they make my classroom more student-centered or allow me to do things I can't already do given a computer and a projector.

While smart boards are undeniably wonderful eye candy and there are some good uses for them I have recently begun to question the value of the smart board. A quick google image search almost universally shows one person using the smart board and many others watching them... Ugh. That's not what I want my classroom to look like.

Is this photo doctored?
Check out the teachers shadow...

Have smart boards simply become something that teachers expect to have? Are smart boards really changing the way we teach? Are smart boards allowing students to learn more or in different ways? How does a smart board allow a teacher to create a more student-centered classroom? How does a smartboard beat a tablet and projector?

I am not an anti-tech guy, far from it, but I don't want technology for the sake of technology. I want technology that improves on what I can already do or even better lets my students answer questions they couldn't previously answer...

What are you doing in your classroom with a smart board?