I had 3 pdas over the past couple of years..
First, a Casio Cassiopeia E-125 - used it for a to-do list, notes in school, mp3 player... was stolen from me.
Year later, i bought a Dell Axim X5 advanced, used from ebay. Broke it after a week, crushed the screen against something when it was in my pocket. Sold the motherboard out of it on ebay, almost made up the entire loss.
Maybe 8 months ago I bought a Dell Axim X5 basic, again used from ebay. This one worked fine, and I had plenty of accessories from my old x5. I used it for mp3 playing, maybe a little bit of a to-do list... then i didn't turn it on for a month. Figured I didn't need it, so i sold it.
To me PDAs are one of those toys that you always want, but with little practical purpose. Yeah, some people have a good use for them, but i dont.