Pickers might be the show Richelle is thinking of actually.
Top idea, I used to do it with a mate years ago lol, and we made some sensational finds. Trouble with us was that we really didn't know what the value of anything was back then, it was more some fun for us. Getting in amongst all the gear stashed out in the old sheds lol, we had a ball!
We did well with old signs, but we scored two cars one week. Our most successful ever week, made us a grand or so each that week, and I'm talking about 1979 lol
I remember I bought a car, a new stereo and went to Adelaide for two weeks on that weeks earnings lol, thought I was rich :)
Just bare in mind that was all just local newspaper advertising as well, we didn't have any eBay to help us cash in, damn it lol