[njsteve]

If you can pull out the key, the lock cylinder is bad. Immediately replace the ignition key assembly. You have to pull the steering wheel to do it but it is rather easy if you have a repair manual. Go to a locksmith and buy the new GM lock cylinder with key. Don't bother with the aftermarket ones. They tend to have quality problems such as missing things like an accessory position. (I learned that the hard way).

I always replace all the locks when I buy a car - common sense safety precaution. It's also just as wise to do it when you move to a new house or apartment. You never know who has old keys.