Bump Key, How To

This technique is well known within lock pickers, and locksmiths. It is called Bump keying. You can even buy a Bump Key from some companies. But, I chose to make my own. What you need:
1 Key, with the right shape.
1 File, Correctly sized.

File the key down until you go just a hair past the lowest peak on your key. Which should be right above the grove. Then File down little notches where the valleys used to bey on your key. It helps to mark these before filing.

Insert the key into the lock, give it light pressure, pull it out one click, so it has room to knock into the door. Then, while applying light pressure as if you were tyring to unlock it, Bump the key with the file, or something else hard. After a few trys, or the first if you are good, it should turn like your normal key.

The reason this works is because in your lock you have little pins, and these pins push up other pins attached to springs. So when you bump it, it works much like billiard balls. When you hit the bottom pin, the top one jumps. And when this happens, you are able to turn the lock, but only while the pins are knocked up.
Masterlock has started adding awkward pins that cant be bumped. But in any lock that was made pre 2007 this will work wonders.
Mine will work on my house, and any house in the general area, if I was feeling mischievous. It just needs to have the same number of pins as my key, and the same length.