If you want to kill yourself Sand Person #10, drive into your garage, put it in park, close the garage door and hit the gas. You'll be gone in about 10 minutes, painless!
anyways....
Jumping right before the elevator hits the floor wont save your life. I saw this done on 'Bill Nye the Science Guy'. Except he used an egg to demonstrate.
BankOne is right, it's all about momentum!