As I'm sure y'all remember, I bought a house this past August. At the time, we discovered that some of the 3-prong outlets were not grounded. We figured that we'd have to re-wire most of the house to correct that issue.
Also as I'm sure y'all remember, my brother, the electrician, is currently staying with us.
He was fixing one of the outlets (a standard outlet was wired as a plug that plugged into an ungrounded outlet in another room) and discovered something. All the wires leading to the breaker panel are grounded. The ungrounded outlet that the extension outlet was plugged into had a ground wire, it just wasn't connected to the outlets. He checked an ungrounded outlet in another room, and discovered that it did have a ground wire connected to the outlets, which means that the ground wire was disconnected somewhere between the outlet and the panel. So now all we have to do is get up in the attic and trace the wires and connect the ground wires, or connect the ground wires to the various plugs. Either way, it'll be much cheaper than rewiring the whole house.