We use touch screens in the kitchen and all bathrooms and iphones everywhere else. My list is ordered by how often we use each.
Multizone distributed CD quality audio
Multizone distributed HD Video
Security, Surveillance & Fire/Life Safety
Resource monitoring (electric, natural gas, water)
Family calendar and reminders
Meal recipes, cocktail recipes, shopping lists (kitchen touch screen - shopping list to iphone)
Health Tracking: Weight, BP, running, bicycling, etc (bathroom touch screens)
Lighting (most lighting is scheduled but we use touch screens to set scenes, control remote lights and set lighting schedules)
HVAC (mostly scheduled, same as lighting)
Formerly CID - switched to all cellular, dropped land line - no more spoken CID but doesn't matter when your phone is in your pocket
Very minimal use: Weather, News, Sports, Finance, photos, web, email, etc. I thought this was very cool but no one else did. After awhile I found that even I didn't bother to look at it for this. It was easier to get this info through other sources like cell phone, computer or TV. I filed it in the category "just because I can do it doesn't mean I should do it." Different strokes for different folks.
Rick