Im not sure about the first guys car since he never said make and model and year, but for the Pontiac, it sounds like the ignition switch has gone bad.
In both cases, we think of the tumblers as a sure bet that they have gone bad and not allowing the key to turn. Not always true.
Lets do a few basic things that can clear it up. Manual release! Should be on the bottom of the column like the first guy referenced. If you can manually release the key, then your tumblers are not the problem (most likely). So, on to why your key wont come out. In most cars they have a park position switch that supplies a ground to the key unlock solenoid to release the key when you are in park. If the car would run and everything is perfect except the key wont come out, then I would suspect the park position switch as being bad. But, since you have totally lost power, then the solenoid has no power to release the key. Now to the problem at hand. Your ignition switch seems to have gone bad, and not supplying the car with power, which includes the solenoid to remove the key.
Now, I would make sure your battery is not completely dead. I have seen them short internally and just have no power what so ever. That two will fit the symptoms you describe.
Please post back the fixes to both of your problems and maybe I can learn a little also.
Monday, July 31st, 2006 AT 7:17 PM