Yeah, I don't have a data plan. I look for free WIFI if I need internet.
Not to say that this doesn't work for you, but having a data plan is completely different. Being able to count on the fact that, most of the time, you're able to pull your device out of your pocket and access the internet, whether it's for email, maps, or looking something up is extremely valuable.It may not be worth the cost for some people, but I will say that before I got my iPhone there were many times where my strategy of "open laptop and see if there's free wifi" failed to work, and occasionally involved driving to the nearest McDonald's trying to pick up their wifi from my car. Not fun.
Having your phone always on and always connected is a very similar transition as when going from dialup to broadband. No more "I'll look it up on my computer when I get home", instead you can just look it up right now, anywhere.
Once I cancelled the plan, I soon realized how little I actually NEEDED to look something up on the go. It's a lot like how I got rid of my car and all associated expenses after realizing how little I actually drove it. Now, if I need a car, I'll rent one. That's only happened once so far.
It wasn't until I went to college and had a persistent pipe that I finally got how different always-on internet was compared to internet you had to bring up.
I suspect at least some of your lack of use for a smartphone is precisely because you don't have a data plan.
I don't text. I don't IM except at work, and emails can wait till I get home. It is handy to have a web browser for when you absolutely must look up something on the go, but honestly that doesn't happen often enough to warrant a hefty data plan. Yeah, I don't have a data plan. I look for free WIFI if I need internet.
So what else is there? Reading books? I do read books on it (while on the go), but it's generally an unpleasant experience because the screen's so small that it renders everything at the subpixel (read: blurry) level and I spend all my time either squinting or doing zoom-in-and-pan.
Tablet? No, thanks. If I wanted to lug something big around, I'd take my laptop with me. It's far more versatile.
Games? Meh. I still haven't found any really compelling smartphone games. And really, if I wanted to play games, I'd just play them on my laptop or desktop, which have better specs and bigger screens and better input systems.
Camera? Well, I've taken some photos with it, but I don't use it often. I suppose it could come in handy for that one time when i REALLY need to take a picture.
The things I DO like are:
* note taking * voice recording * learning apps * Being able to transfer stuff onto and off the phone without too much hassle
Aside from that, there's not much I find compelling.