In my case, I compared the prices and services to my land line about a decade ago. It was easy to see which would be more economical and I haven't had a land line since. If I don't want to be reached, I'll just switch the cell phone off. Currently my cell phone is provided by my employer. I'm considering buying a waterproof device for private use, for paddle / bike tours. In our case, none of the really sensitive information is stored in SIM card, so I'm free to switch between devices if I choose to.

Security issues have been discussed at work. All our cell phones and laptops have strong access control / encryption software installed, which does make them a bit tedious to use occasionally, but gives some peace of mind. A briefcase full of documents, or an unprotected USB memory stick both have more damaging potential than our mobile devices.

--J