I agree with the idea that it's hard to figure out how useful a PDA would be to you, just by thinking about it. I
very reluctantly moved from paper to a PDA, mostly to have a smaller package where my calendaring, contacts, etc. were all in one place.
I didn't realize how useful the thing would become to me -- not because of the calendering and contacts, but because of all the other great features. If I hadn't looked around to see what else was out there, I'd have found the PDA only somewhat useful.
As it is, now I can't live without it. Coupled with a small folding keyboard, I now take all my meeting notes on it, isntead of lugging around a laptop like everyone else. I take my notes in Word and upload them to my PC. I also keep all my most-important word and powerpoint documents right on the PDA, so I have them all the time. I also download web pages to read offline when I'm waiting in lines, waiting for my wife shopping, etc. Lost? No problem, I have a map of the entire county on my PDA, including driving directions from one address to another, landmarks, address lookup, etc. I have several very useful calculators, I can download and read my email, I have all my important passwords and financial information in a triple-DES encrypted database, I have a bunch of games (hey, all work and no play, and all that

), databases that contain all kinds of useful info on many different subjects (area codes, zip codes, 800 numbers to hotels and airlines, etc.), etc. etc. etc. Plus, it's often useful to attach the PDA to a cellphone and browse the web or email wirelessly, or send email.
That really is just the tip of the iceberg. I have a ton of other good stuff on there that I use all the time ... of that's just nice to have, even though I only use rarely. I'm enough of a fanatic that I feel that anyone who hasn't found a PDA useful probably just hasn't looked closely enough at all the great add-ons you can get that make the PDA convenient.
Joe