A couple of things I've done/thought of:
Garage door timeout (post in gallery). Very simple, yet practical.
Internet enabled just about anything (HVAC, Sprinklers, Pool, Doors, Lights, Etc..)
I'm thinking of setting up my office so that when I walk into it, the light turns on, Music turns on, blinds open and Computer is awoken from sleep.
RFID access to your house.
Photosensative porch lights.