A few of us have been feeling uneasy about our front door security and how weak the original locks are.  Tom Walthrop found a lock on Amazon called Nightlock that drills into your floor and is able to secure both doors at once.  The locking mechanism is just a brass plate the slides in and out of the base, making it easy to remove when you need to use the door.  I installed mine in about 5 minutes using my drill.  It definitely makes me feel safer in my house.

 

Amazon sells it for about $37.