Basement bathroom door for cleaning supplies. Kitchen to basement door for pantry items. Back of girls' door for barbies. Inside girls' closet for shoes. Inside my closet door for belts and scarves. Entry door for shoes, mittens, etc.
Lockitron - a mobile phone operated door lock that fits over your existing dead-bolt. Keyless entry into your house, notifications of missed house visitors or deliveries, let your friends / family into your house remotely, etc. Love this concept.