Jon Udell writes:
For years I've entertained a fantasy about air travel that I'm sure many of you share. You're staring out the cabin window, watching the landscape scroll tailward, and some feature catches your eye: a building, a highway, a lake, a ridge. You touch the window and a heads-up display fades into view. It's kind of like Google Earth, but live and in realtime. You summon and dismiss layers of annotation, and you bookmark locations for later study.