I'm a brand new home automator/Indigo-er. In fact, I'm so new, I haven't even started yet. My Indigo Pro Starter Kit arrived at my house yesterday, but I won't be home for a couple more weeks to play with it
I've also got an iPhone on order for my arrival back home. Big ideas and big plans for home automation. Reading all of these great suggestions and plowing through the Smarthome Hacks has got me anxious. So here's my first major project outside of getting started: facial recognition at the front door.
iPhoto/Faces (no internet required) - My initial plan was to tap into iPhoto and use Faces as my facial detection/recognition. Since iPhoto doesn't have an API, I tapped into the faces and similar_faces databases that it maintains. This worked with moderate success until I realized that the facial recognition is triggered by user-interaction rather than programmatically. I used the UI recorder, and got it working where I could take a picture of myself and have it identify me with a level of confidence then spit out my name. Long story short, its janktastic and only identifies the people I click on during the UI recording session.
Face.com API (internet required) - This solution is slightly more elegant, robust, and expandable. The only downfall is requiring an internet connection for it to work. Face.com allows you to train faces to be recognized later. So far, with some help of Automator and AppleScript, I've managed to automatically snap a photo using the iSight, upload it to my webserver, ship it off to Face.com and identify my face. Pretty sweet.
Ultimately, I'd like to have a motion sensor trigger a snapshot of the person walking up to the door, identify their face (my own or family members'), and unlock the front door.