Car won't shut off...Help!

So, I've been trying to drive the barracuda more lately, and all of a sudden, after two days of driving it, it doesn't start. I jump it, let it run for 20 minutes and then let it sit for most of the day. I go to pull it in the garage at the end of the day and it's dead again! I jump it again and pull into the garage. When I turn the key and pull the key out it's as if i hadn't done anything. It just keeps running. I replaced the ignition switch; no dice. That was $60 down the drain. Could it be the coil? Any help would be appreciated.

Thanks,
Grant
I absolutely need to continue reading the rest of this thread because if I only read this, my first question would be has the car ran out of gas yet? Cuz nowhere does it say you got it actually to turn off!
If someone says grab the Coil wire! Don't do it! I told that to a friend in high school auto shop and he damn near peed his pants! Our teacher mr. kingham damn near peed his pants laughing.