Sure, those leather binder things look nice, until you leave it sitting on a restaurant table...
I just don't understand carrying redundant things, myself. Cell phone makes a great watch, calendar, flash light, camera, nav system, etc... Plus I don't have to make out my crap writing and can copy/paste and alter appointments with ease! Not to mention reminders. Also love automagic sync with everything I"m logged on to.
And the smartphone calendar functions keep getting better. Google has stuff now where it automatically scans your email and reminds you/provides details for things (especially flights) that, yes, is creepy, but also works really well!