EYES

Think about this.  Technology usually leads common use by 10-30 years.  That's the length of time from a scientific discovery or invention to the time it is generally available to the public.  Big computers were available in the fifties and sixties.  The computer wasn't put to general use until the eighties and we didn't really have personal computers until the nineties.  Jet engines were developed in the fourties but we didn't see them on commercial planes until the sixties or seventies and they weren't available in small private planes until the eighties. 

Now think about this.  The U.S. has had a telescope orbiting the Earth for a number of years (the Hubble telescope) that can take pictures into deepest space, millions of light years away.  With this technology, they must have the capability to see each pore on the skin of your nose from up there. 

If you don't play with Google Earth once in a while, you're really missing something.  With it, you can now see 3-D pictures of most of the Earth -  for free.  Just imagine what is to come.
:-)