I love my Palm Pilot. I would never be anywhere on time without it. I'm just too focused on whatever I'm doing. That and a really poor memory.
Try as hard as I might, I could never get a paper and pencil appt book to beep at me.
I hardly ever write anything directly into my pilot. We use Outlook where I work and all my meetings are already in there. I just sync up and I'm good to go.