Google just added a "Street View" feature to their Google Maps application. Now you can seemlessly navigate through street level photographs all over several major cities.
Click here to see the lot in West Farms where we did Team Up to Clean Up. (These photos were taken a few months ago - you can see the grafitti and trash that was on the lot before our clean up.) If you click on the arrows in the upper left hand you can look all around (360 degrees) or zoom in. See that yellow line floating in the middle of the street? Click on the "East" or "West" arrows and you can take a virtual walk up or down the block.
Here is an interesting article about a system developed by an L.A.-based company that uses digital photography, GPS navigation, and a computer database to track grafitti crime.