Like most people that are serious about them I put everything into my pda (HP Jornada 568), However, sometimes I'm in a situation where it is convienent to do that. Or I just might not be in the mood too do that. That's why I usually carry a notebook along with my pda.
I've been getting, and buying, stuff from Levenger for years. I never bought one of there notebooks. I got a "padfolio" for Christmas a few years ago and I like it a lot. It's bit large to stuff in your pocket though...
After work I went out and bought a small moleskin notbook and I think it is going to work perfectly. It's slightly larger than 3x5 inches, has a hard cover and the paper is smooth as silk! Plus is has a certain mystique about it. (If a notebook can be described that way.)