You will pry my cell phone from my cold, dead hands...
I don't text a lot, but I do send a few a day. It's quicker and easier than a phone call for things like, "Hey, I'm going to be late today. Meet me at X instead of Y." Plus, more often than not, when I'm able to send that message, the other person is not able to receive it. So, this way, he/she can check it later instead.
I also use my cell phone to VERY quickly delete all email I don't want to read. Instead of logging into several email accounts each day, I only log in if I actually want to send a message (of more than a few lines - I send the short ones on my cell). Well, I also have to log into my work email, since they won't let us put those on our Blackberry. They have them set up somehow to restrict that.
My cell phone also means that I always have a few dozen books with me. This means that I always have a useful way to occupy my time. I use an eReader, otherwise, but for times when I need something to do other than stare at a wall, I can always pull out my Blackberry and read a book. I can also use it to check the path of the tornadic outburst to see if it's safe to go home and I can use it as a GPS if needed. (I don't own a separate GPS. I don't particularly like them but will pay for a day's pass to that service on my cell from time to time.) I always have maps of every location at my fingertips with my cell, even if my well worn paper maps don't cover the area that I'm in that day.
I have no landline. Just my cell.
And, text while driving? That is so passé. With dataphones you can do so much more than text while driving...
(No, I don't do either...unless I'm stopped to wait for a train, in which case I make no promises.)