I’ve recently been shown where the state of Montana’s website has a lookup utility that allows you to see the ownership, tax value, etc. of different parcels of land. It’s a pretty neat website they put together, and quite interesting to browse through.
On a (sort of) related note, the Environmental Working Group’s website has a Farm Subsidy Database. It’s a truly massive database, and very interesting browsing. You can find out how much money has gone to farm subsidies, based on state, congressional district, and county. You can even track it down to the business entities receiving subsidies.