This is a bit off-topic, but I really enjoyed William Gibson's Spook Country and especially was intrigued with the headsets used to overlay 3D renderings on loc

This is a bit off-topic, but I really enjoyed William Gibson's Spook Country and especially was intrigued with the headsets used to overlay 3D renderings on locations via a GPS-enabled server. Ray Kurzweil talked about VR visors, but I think adding GPS massively increases the value of th eidea. I have since had several bursts of musing on locative art, entertainment and education (particularly history lessons).