Google Earth allows you to view a global composite of satellite imagery.  Live imagery is not available publicly as far as I know.  Live imaging is generally military.  Google Earth is pretty cool if you are not needing live images.  You can generally make out your own house, though resolution is better in some places than others.  You can see crashed planes, sunken ships, and a bldg in San Diego's naval base shaped like a big Swastika.
 
However, even if live imaging were available, imaging satellites are not geosynchronous, so they do not stay over any position for long term observation.  To view a particular location, you have only a "window" of time to view any area. The closer a satellite is to earth, the faster it must go to remain in orbit, and surveillance sats are extremely low.    Geosynch satellites are used for such things as satellite TV and GPS.