Well there was a time when I ran a transport business that I couldn't do without them. They are so useful for getting in touch with drivers out on the road, and it means you can give a customer a realistic delivery time, instead of guessing, which was how it used to be. The result of this was an unhappy customer in most cases.
I still have one, but now it's a combination PDA/Phone/SatNav, that way I can justify it a wee bit more, and I DO love gadgets!
Giok