I don't have a phone other than my cell phone
I turn off the ringer when I'm at work and I don't answer it when I'm busy, but it is the only personal phone I have, so it is the best way to reach me. I resisted getting a cell phone until I started law school (my philosophy was that only doctors and drug dealers need to be that accessible). The school's phone plan was so limited and so expensive that the cell phone was significantly cheaper. Now, I'm pretty much expected to have a cell phone so that work can always reach me and I have absolutely no use for a land line.
My job also provides me with a Blackberry, so I'm always getting my work emails, no matter where I am. It is a bit annoying being that connected to work, since it seems I can never escape it. On the other hand, If I'm not busy, I can always leave and know that if anyone needs me, they'll be able to get in touch with me.
