Folder with Question Mark On Startup, Don't Know the Firmware Password
Note: This RAM change trick no longer works on 2010 or newer Macs. I haven't done this in many years, but it did help back when I needed it. 

If your laptop is old enough, and you can easily get to the RAM, (depending the model):

Shut down the Mac

Disconnect the power.

Open the MacBook and change the RAM configuration. Add or remove RAM so the amount is changed. Since the HD is dead, you won't need to have minimum RAM to boot OS X.

Close up the MacBook.

Start up and reset the PRAM by holding down Command+Option+P+R.
Hold these keys down continuously until you hear the MacBook chime 3 times. Release the keys.

When you see the question mark/folder, power it down by holding down the power button.

Open the MacBook and reinstall the RAM, as well as a brand new HD.

Close it up.

Restore the OS with the installer of your choice.