"Through process of logical deduction, acoustic energy is the only type of energy that can be used for over-distance wireless power transmission. Since uBeam owns the entire ultrasonic wireless power space from an IP perspective, the world will have to leverage uBeam’s technology."
You're right that yearbooks are not terribly useful on a day-to-day basis since it's static. However, I think Facebook's value comes from the organic nature of the site. You can update and craft your social graph to how you see yourself interacting with different groups of people at a given point in time. Of course your social graph will morph over time -- Facebook will hopefully make that as frictionless as possible. Facebook is a history of yearbooks.