I too use pre-paid only. I pay less than $7/month w/Virgin mobile.
I do look longingly at smartphones. But it's just not worth it for me with current structure of plans. They're either voice-centric, which i'd never use, or data-centric in ways i don't need.
i'm near a computer w/internet access most of the time.
I love the Internet, and do all the dorky social networking things that make me somebody who should be slurping access from everywhere. I'll gladly drop bank for something that fits me, but i'm basically waiting out the entire old school phone system :D
In the meantime, i have a bad phone. I bet there will be Android phones soon on the big pre-paid systems.