I got a factory style key blank from http://www.autotransponder.com/2009_155
My local Ford dealership cut the key for me for a nominal fee (forgot how much but it wasn't much). I did the programming myself.
On a related note, as long as you have two keys, you can add a third to the security system by yourself. If you only have one working key, you will need to go to a dealer or locksmith to add one. I highly recommend that you go ahead and add a third (spare) key before you loose one of the factory two.