Battery Life

Here's an interesting tidbit- talking on the phone is actually the activity I do the least on my smartphones. I'm not a big yakker, and I have such a short attention span that I can't keep up with a long conversation. So the specs that constantly refer to how many 'talk hours' a battery/device has is of no real value to me.
But I do use my pda extremely heavily in the course of the day. In fact, my iPaq is lucky if it gets to stay off for a full hour! It tells me every single task I need to do for the day, plays my internet radio, gives me my news, my ebooks, streams my video podcasts, gives me my Twitters, and has my IMs and texts going all day.
The truth is I don't know how many hours of use I ought to be getting from my devices. Ideally I would love to be able to get a full day, but I realize that's asking for a lot. Even when I was working, my pda spent most of its downtime in a charging cradle.
I recently purchased an extended battery for my iPaq, but I'm having a hard time aesthetically with the hump. I scored a spare standard battery on eBay for under $20 shipped, which I plan on using for the second part of the day as needed. (I'm trying to decide whether or not to get rid of the extended one.)
In the future I would like to see not only longer lasting batteries, but also more measurement units that reflect the way that I typically use my smartphone devices.