Does technology really impact learning?

I have been contemplation technology in the classroom a lot, as it is going to be the focus of a project for one of my graduate school classes. 

Utilizing the Smartboard in my classroom has been interesting.  I love it for some classes, and find it to be a glorified whiteboard during others.  It draws attention, good and bad for my students.

However, does the cost really correlate to the learning impact?  This I am not sure of, and am leaning on the side of no.  Lessons are engaging, however could putting an iPad or laptop in the direct hands of a student have a greater impact?  For the cost of my board, my school could purchase 8 iPads or 4 laptops.  These could impact student learning in all classrooms, not just mine.  Additionally, aren't these the tools that students need to be utilizing with as they are the real world tools they will use beyond the classroom?

I love technology, and always have the lastest and greatest.  However, I think sometimes people adopt technology into schools without full thought to how it will be utilized in direct practice, how it will directly impact student learning, and what the end goal will be with relation to its use.  Most public schools have interactive whiteboards in the classrooms, but how much are they fully being used and what evidence is there that student learning is improved by them?

In considering the adoption of iPads, I read about many schools that have jumped in with 1-1 programs, but what data is being collect to demonstrate that the use of them is directly improving student achievement? 

What do you think?
I would love to hear from educators concerning these issues.  What do you see?  What proof is out there as to the true growth of our students development with these tools? Are students truly using them to engage in learning or to just engage in interacting with the technology? 

21st century learning should include technology just because technology exists.  It needs to be used to directly impact student learning in ways that could not be done before.  It needs to level the playing field for a variety of learning styles and needs.  It does not need to be there because students only know how to learn with technology.