Check out this Tech Article from the Pelican library. It explains exactly what needs to be done to re-key your locks to make all your locks match one key. It sounds pretty easy. Unfortunately, I don't know where you can purchase the assortment of lock pins needed to do this.....if you have some old locks laying around, you can cannibalize the pins from them. Some people suggest that a good locksmith can do it, but I don't know any around my town that can. Maybe the Porsche dealer? I shudder to think what that might cost, if they can do it. If anyone out there knows a good locksmith that can do this, or where the lock pins can be found for DIY, please post a recommendation.
http://www.pelicanparts.com/techarticles/mult_lock_rekey/mult_lock_rekey.htm