I usually do take my iPhone with me when going out of the house, especially when driving somewhere, not so much in order to receive calls or check my incoming email but rather to have the phone to use if there is an emergency situation and I need to call someone. Also, in the car, the iPhone does act as my music provider, too, through the stereo system in the car. If I'm just going out on a walk around the lake and shooting photos I usually leave the phone at home since I won't be gone all that long and the phone would be a distraction if I did receive an incoming email or call.
As for FB and Twitter, I have accounts on both but tend to neglect Twitter, and only check FB because I am in a couple of groups on there which are related to subjects of interest to me. Also I do keep in touch with a few distant, not-close friends through FB rather than through emails and texts, but the majority of my contacts are through the latter. I keep my FB account pretty locked-down and private, too, and my friends list fairly small.
I rarely write anything personal about myself on FB and took the precaution of providing a different birthday/birthdate than my actual one. For a while I got away with using Clix Pix as my screen name but they eventually nailed me and insisted that I use a real name so I relented on that, but going with the shortened nickname version of my first name rather than the more formal one.
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