I don't go out these days without my phone. My OH reminds me to take it, so I can ring if there's a problem with the car (it happened once) or if I pop into the supermarket I can give him a bell to see if we need anything. I look at my forums on it, use texts and messenger, and play online scrabble!
I sometimes use the camera, particularly if I'm with the grandchildren. Modern mobiles are fantastic IMO.