I realise the thread is phone phreaking related and that was kind of the point of your post; but in the spirit of the talk below to think more outside the box...
This is a good related talk - goes outside the box on all the ways you can often get into commercial buildings without picking (or even in many cases, interacting with) the lock
"The Search for the Perfect Door" by Deviant Ollam
https://www.youtube.com/watch?v=4YYvBLAF4T8
There's a pretty good chance in many cases you can just open the external box with some easy to get (and relatively standard) key. And hit a button. Related: https://twitter.com/MalwareTechBlog/status/90382347816752742...
This is a good related talk - goes outside the box on all the ways you can often get into commercial buildings without picking (or even in many cases, interacting with) the lock "The Search for the Perfect Door" by Deviant Ollam https://www.youtube.com/watch?v=4YYvBLAF4T8
Also good: https://www.youtube.com/watch?v=a9b9IYqsb_U [Howard Payne & Deviant Ollam - This Key is Your Key, This Key is My Key] https://www.youtube.com/watch?v=oHf1vD5_b5I [DEF CON 22 - Deviant Ollam & Howard Payne - Elevator Hacking - From the Pit to the Penthouse]