I tried this with a lot of localities registering cities and towns in the .info extension. My theory was somebody has got to have an interest in these even if they are not .com. They were great because they were only $0.49 a piece to register. At this point I have yet to sell one even for a few bucks. Part of that is a terrible extension but the other is because I have not even had the time to try to sell them to the appropriate people or channels.
As Stub mentions I have heard of people making some great transactions this way. I guess I would say to be a head of the game. If you see a local opportunity, pounce on it before others do and then come out with the domain name for sale, preferably in the .com. Stay away from the other extensions in this instance like .co .pro .tel .ws etc. Best of luck to you! Send me a PM if you want some help and advice.