The dealer has to plug into the car's computer & program it to accept the
new/all the keys.

When they do it, you need to bring in all the keys.  Any left at home will
no longer be valid.

You should be able to get 2 (or more) $29.95 keys made at once.  It should
be a flat rate
to add them all at once (flat fee (1/2 hour labor?) for any number of keys
to be added...)

on 3/26/2009 1:53 PM (ET) Kevin Marsh wrote the following:

Some of the newer chipped keys are side notched rather than edge
notched. They all may be side notched, but I don't know. I also don't
know if key making machines are able to make duplicates of the newer
side notched keys. If you can find someone that can make a duplicate,
you won't need to have it programmed because you don't need a chipped
key to unlock a door. That would only be handy if you accidentally
locked your keys in the car. I keep a spare key in my wallet for just
that purpose (I have an aftermarket keyless entry system), but I don't
have chipped keys in my 97 PU.