Great, thanks for the info! I've actually acquired a couple of dishes this way recently, this one and a 10 foot C-band dish. Both were lucky finds but the C-band one was a bit amazing in that you could just barely see the dish from the road. I was driving by on my way back from a nearby town that I haven't been to in quite some time, and I deliberately took the back roads to look for dishes, but when I drove past this one it almost didn't register at first, then a bit down the road it was like my brain had processed what my eyes had seen, and the thought hit me that I had passed something that might have been a dish. So I turned around and went back and sure enough, the dish was in the side yard of an abandoned house and hardly visible from the road because of trees. The house was clearly abandoned but there was a house across the street so I knocked on the door there and it turned out that the neighbor knew the owner and was able to give me his contact info. I called and left a message a couple of times and figured he must not want to get rid of it, then about two weeks later he called me out of the blue to say he didn't want it and I could come and get it as long as I didn't take the pole (apparently he had other plans for that).
It wasn't the best dish I've ever had - the ribs seem to me made of relatively thin material and there were already three stress cracks along the edges, and it has a buttonhook LNB mount, but at least all the panels are there and there are no significant dents, and once I got it up it seems to work pretty well (definitely much better than my 7.5 footer). My only concern is whether that buttonhook mount will sway in heavy wind (it wasn't stable at all when I was trying to peak the LNB). The funny thing is that the dish actually has holes for mounting four support arms, but still came with the buttonhook mount. I'd almost be tempted to buy four pieces of small diameter metallic electrical conduit and try to fashion LNB supports, but have no idea how one would calculate the correct length, or get the bends on the flattened parts at the correct angle, and for right now it's working well enough.
The story on that particular house was that it had been purchased by a guy with the intent of fixing it up and selling it. He got as far as putting a new roof on it and then went to tackle the kitchen and discovered that whole part of the house had significant dry rot. So now he comes out and mows the grass about three times a summer, I guess trying to decide what to do with it, but in any event he hadn't been the one to install the dish and he didn't want it. So if you live in a rural or semi rural area you might spot dishes in that type of situation, the problem is that many are completely hidden from the road. This house was on Google Earth street view but even looking directly at the house you could not see the dish in Google's pictures. Until the aerial views get to the point where you can count the shingles on the top of a house, finding a dish that way might be a problem. You can't see any of my dishes using the map services of Google, Bing, or Yahoo. So I doubt you will find much that way, but not saying it would be impossible, particularly in areas with better image resolution than in my neck of the woods.