I guess it is practice because I have VERY short fingernails and I move the 5-way with no problem. What I do have a little problem with is the wake-sleep switch. I actually let the nail on my right hand index finger grow a bit to help me with this!
Come to think of it, I do use my right index finger nail for that too, patrisha.
I've gotten used to the 5-way controller with time. In the beginning, I had heard it described as a joy stick and I guess I thought I was going to be able to place the flat of my index finger on it and easily move it in any direction. That is not the case. It's more like a 5-way clicker and I have to use the edge of my index finger or thumb or a fingernail to push and pull it in different directions. But, as I said, it's second nature now.