I don't know if this idea has been presented before but please excuse me if it has. I don't know what it's called, I looked everywhere but i couldn't find the name so please excuse me, but you know the space where the spring and driver pin sit? what if there was another on right next to it that uses the same key. So that way, if the key is in, it will pass by without any thing happening but if the lock was picked, then the lock would lock right back up and it would have to be picked again since there is nothing holding all the keys in the right spot. This would make it longer and more difficult to pick. Or if there were multiple one placed on after another and the plug just has to rotate more than usual to unlock it to make room for the extra spaces that holds the pins and springs.
Admittedly, it would be a bit bulkier than a normal lock, but i would guess that it would seem more secure because it's like picking several locks in a row. And if the springs pushing the driver pins for the second set are particularly strong, then feeling the pins to pick them would be a harder task to do since there has to be much more tension and more force to push the pins. Plus, if someone picks it and it locks up at this spot and is not able to successfully pick it again due to the force required, then the owner of the lock would know an attempt has been made.
Im new to lockpicking and if there is an obvious error, then i apologize as i do not know how locks work as well as most of you on this site.