I live in a college town, and kids will throw away stuff that is in perfect condition when they move out of their dorms or apartments, especially furniture.
Last spring we were driving through a ritzy neighborhood and saw three computers sitting next to the curb with other garbage. We thought for sure they'd be broken, but all three worked and had wireless cards and everything. We gave two away to charities and kept the other. We couldn't believe someone would throw them away.
Today we found a working iron, and a bunch of furniture that had nothing wrong with it next to the dumpster by our apartments.
What cool stuff have you found in the trash?