I use one, because I need to write down times, coordinates, and other stuff, and I need a pad handy. I see no need for anything fancy, though. I have a cheap clipboard cut down to size, with some elastic and a fastex buckle attached, run through slots I cut in the sides. Most of the time it's slid to the side of my leg, but I can get it back on top quickly when necessary. It's a convenience more than a necessity, but I'm all for convenience if it's not at the expense of utility.