Just wanted to bump up this thread again......any advice is appreciated. (how do you program a key?)
programming the key is simple:
1. insert original key into ignition and turn car on
2. turn car off and remove original key
3. insert new key and turn engine on
it has to be done pretty quickly, but its really easy to do. also you can get blank unprogrammed keys for around $10 on ebay. just do a search for chevrolet cobalt blank keys
make sure the keys you order are listed as compatible with the cobalt and have the (+) sign on the shaft of the key and you'll be fine. I ended up buying 2 keys for $5 each, paying walmart to cut them, and then programming them myself.