Misses the point, though: going from "lockpicking n00b" to "master safecracker" has never taken more than half an hour or so, and in order for these services to be effective you need access to someone's keys. So basically - you're in trouble now if you have friends who are creepers who you have somehow given your keys to but you only want them to have temporary access to your keys, not permanent access. As far as the car - whatevs. I've got a '95 Dodge Stealth and it has a valet key. Won't open the doors, won't open the glove box, will start the car. Give the valet that and he never even sees the rest of my keys, and the key he's got won't open the car door. And as far as the house: Any lock on this page will allow you to set a 1-time passcode that will permit your "friend" to get into the house exactly once. Can't remember who said it - "locks exist to keep out the polite." Still true, even in the age of 3D printing.