Here is what I am talking about
http://maps.google.com/maps?q
See the tab with "street views" in the map screen. It is next to "traffic, map, satellite and terrain" directly in the map screen. In certain areas "such as Detroit" you can type in a street address and tour the neighborhood (try 1520 Alfred, Detroit, Michigan for example). You can not take photographs off of the system (which does not bother me because that is not what I use it for) but you can qualify your comps to see if they are practical to use. It is a very good tool if your area is covered by Google. It is similar to driving the area without moving from your desk. It saves hours of driving (especially for commercial properties). Many time commercial comp data systems do not have photographs and you end up throwing out half the comps after driving them.