I honestly do not understand the folks who wear their phone headsets as if it were a fashion accessory. I mean, sure if you are working and need to use the phone, I can understand. It still looks stupid, but at least there is a reason to justify it.
Also, it doesn't help that the manufacturers insist on making these things in goofy slick metallic blue and similarly ugly colors / finishes.
I have a cell phone, but as nat said, it is an "electronic leash". Sure, I love that my family / friends can reach me. But, unfortunately, so can colleagues. No, you can't keep your # a secret forever. Believe me, I tried. But sometimes you make mistakes, often at desperate times, and then... All Is Lost.
I had a flat tire and called in to work one day. OOOPS! My brother gave my cell phone # to someone without my permission. OOOPS!
I actually did some reasearch (on internet start-ups in southern california) and the notion of Blackberries, phones, email, etc. as "electronic leashes" was a recurrent theme with everyone I interviewed. And I wasn't really interested in this aspect of their work (at least, not initially), so I didn't instigate things.