Apparently you can buy a PK3 key on ebay for like 10 bucks, have any place cut it and program it yourself.
Someone posted about it not-so-long ago. I'll see if I can find the thread.
Beats paying $70 for a new key. And on top of that, a lot of the time you have to pay them to program it too.
EDIT: I was just reading this thread
http://www.grandprixforums.net/f81/engine-stalls-within-seconds-of-starting-28294.html
Could be the fuel pump resistor or fuse. Check the fuse first. Mine blew right after I got my car. I didn't make the connection though, because my car wouldnt start at all after it blew.
But this actually makes more sense because it happened while you were driving the car. My fuse blew like 500 feet out of my driveway. Of course I didn't know that was the problem at the time, so I had it towed to the shop where I bought it. 50 cent fix... DOH!