Case in point, Kinect. It should have been just a play accessory, but it's being used to help people with disabilities, like the wi-Go : http://www.youtube.com/watch?v=B-17jRfX9Sw
And also aiding surgeons during operations as well as helping disabled children interact with their environment with more subtle gestures. http://kotaku.com/5950834/in-japan-the-kinect-may-soon-be-mo...
Just like cosmetics and other "vanity medicine" used in the West can have life-saving applications elsewhere, for now, we get Angry Birds. It may turn out to something else later on.
The point is, cumulative knowledge can lead to great things later on. It's the NASA trickle-down theory.