I use mine for tons of stuff.
The basics are just tons of documents I keep with me at any given time, for instance, install instructions/setup info for some very picky applications here at work. IP addresses and computer names. Hardware/Software lists.
I use the contacts ALL the time, I actually had to send my unit off for 5 days to get a new screen and I couldn't call a couple people because I didn't have their numbers anywhere else. (I sync with my work computer)
I use the calendar occasionally for anything that's more than a couple days away.
MP3s of course. (256mb CF Card)
I read the news on it using AvantGo and Mazingo.
I'm also working on getting some software set up that will allow me to manage our webservers and keep track of them from anywhere, wirelessly. I'll be able to check CPU/Mem usage, start/stop services, check processes, etc. etc.
Right now I have an HP Jornada 548 (that I got from the FS/FT forum of course), which I will be getting rid of soon, due to the fact I have an iPAQ coming in at the end of this week/beginning of next week, I need the expansion capabilities.
I just ordered an 802.11b Access point and card as well.
About being naturally useful, I did have to force myself to use my earlier one a little. I had a Nino with CE 2.11. It just wasn't as easy to use, the interface was clumsier, it didn't have much expansion room, etc. The Jornada though, as I'm sure with all PPCs is very useful, and I end up looking for it because I need it more than wondering what to do with it.
I looked on your profile, and you're from Washington. A good thing to do if you have are near the Seattle area and have a chance is go to a PSHUG (Puget Sound Handheld Users Group) meeting. There are always lots of demos and stuff, and the other people there are more than happy to show you what they do with their device and stuff like that. Sometimes people even have devices or accessories they are willing to sell due to upgrading or whatnot, and you may get a good deal, along with some software or something.
The site is
PSHUG and the meeting page hasn't been updated yet, but there is a meeting at the MS campus on either the second or third week of January. You should come by and check it out. PM me if you want some info, or if you want to find me there or something. I'll show you some of what I do with mine and what some of the other guys do. It's pretty cool.
No admission charge or anything, there is even stuff given away, it's an open invitation to anyone who wants to show up.