This 15-User Fingerprint Deadbolt Lock from SmartHome provides maximum security for your home or business. Just program up to 30 prints, then install the lock on either side of any standard wooden door.

[I'm trying to refrain from more Back to the Future references today, but I just can't help myself. If you remember, in Back to the Future II, Jennifer was trying to escape her future home in Hilldale, but there were no doorknobs. Doc instructed her to press her thumb against the metal plate so that the door recognizes your fingerprint and opens. But, her future self walks through the door instead, and she passes out.] 

With the Fingerprint Deadbolt Lock, you're given 3 emergency keys in case your finger is having a bad day. It requires 4 AA batteries that are good for 300 uses. I wonder how well it works, though? Available from SmartHome for $274.99.