Where do you look to find cars for sale?

I have had the same question. Around here it seems like craigslist doesn't have much. I am looking for a local 73 up a-body to use for a disc brake and rear end swap. I figure I will talk to some picker swap meet car guys, car club members, mechanics, route truck drivers and have them keep their eyes open for a abandoned a-bodies.
Don't forget e-bay(for the most part out here in the sticks project/parts cars on ebay don't sell for high numbers). When I was circle track racing a 86 Shelby Charger, I was looking for a parts car. On a whim I checked ebay and got a complete and running 86 Charger 2.2 for $112 just about 30 miles from me, the seller turned out to be a friend of my brothers.