If you have locked the keys in your car, no need to panic quite yet. If you vehicle has a locking tab mechanism that slides up and down, usually by the window, you can unlock it using nothing but a shoelace.
Step 1: You will want to remove the shoelaces off of a pair of shoes. You will need two.
Step 2: Tie the two shoelaces together by tying a double knot and the end of each lace.
Step 3: Form a loop about 3/4 of the way down the string and tie another double knot.
Step 4: Starting at the top corner of the door jamb with the long side of the string towards the front of the car, slide your lace behind the door. Pull it from side to side until you see the loop inside the car through the window.
Step 5: Position the loop over the lock mechanism. This can take a few attempts.
Step 6: Once loop is hooked around lob mechanism, pull the string tight using the short end of the lace that is toward the back of the vehicle. Lift up slowly until your vehicle is unlocked.