We're still a few years shy of being able to put up personal Earth-observing satellites. In the meantime, you can always take advantage of images from satellites owned and operated by someone else. We've posted about the "Public Eye" project run by the DC think tank Global Security a few months ago, which makes current pictures of hotspots around the world available to the public: timely, possibly informative, but narrow in scope. We've also posted about the ESA making satellite data on land use patterns available to the public: possibly timely, definitely informative, moderately narrow (EU only). Today we have Keyhole, a satellite company recently acquired by Google. Keyhole is making its Earth observation software available for free download and 7 day use, allowing you to zoom from place to place. The entire world is covered, to varying degrees of detail (with some locations showing sufficient detail to pick out individual people). Windows-only, and no longer free after the 7 day trial, but worth checking out.
Biggest problem, though: it's not live, updated data. It's shots from over the last few years, some from as far back as 1999, others from just several months ago. So we add to our list Keyhole: not at all timely, moderately informative, but very broad in scope. And a lot of fun to play with.