Living flesh is innervated with all kinds of sensors like taste buds, pressure sensors, photoreceptors and position sensors in muscle fibers, which monitor internal and external conditions. Brains analyze signals from these sensors using built-in and ever-evolving models of the world (that include the owners of the brains) and then use these analyses to formulate plans of action.
One of the most important un(der)reported stories today is the way the inanimate world built by humanity is becoming ever more innervated with sensors (cameras, microphones, strain gauges, magnetic sensors, GPS receivers, transponders, infrared sensors, satellite surveillance, etc.) as well as communications systems linking these sensors to computers that can store, analyze and act on those signals just like biological brains. What's more, all of these sensors are likely to ultimately link into a next-generation Internet via ultra-miniaturized, on-board, wireless connections (one of the main R&D thrusts of the microelectromechanical systems community). Millions of millions of thermometers, barometers, GPs transponders in vehicles, seismic monitors, radiation monitors, department store surveillance cameras, and thousands of other gadgets watching the world will all feed data into the system. This will amount to a global-scale, sensitive infrastructure a planet-sized body, that is — whereby myriad sensory signals will constantly feed into a global-scale cyberspace coursing with sophisticated pattern-recognition abilities, knowledge-discovery (data-mining) systems, and other artificial cognition tools. One consequence will be that Earth will have a new kind of planetary self-awareness akin the bodily awareness living creatures have due to their sensory tissue. Debate about personal privacy will become almost moot since the entire world will constitute a glass house. On the up side, the complexity of this worldwide awareness — and the new categories of data about the world will become available — is likely to lead to emergent phenomena as surprising as the way life emerges from molecules and consciousness from life.