I couldnt find the option to turn on the battery percentage indicator in OS 3.0 beta 5. I directly upgraged from 2.2.1 to beta 5. didn't go from beta 1 > 2 > 3 > 4 > 5. Is that the reason? How do I get it?
Basically, it's a program for Mac or PC that allows you have root access to the phone so you can do a multitude of things such as changing themes. You have to be jailbroken to use it.
I have an easier solution. There is an app called Free Memory (1.4). It shows a list of running processes on the phone can free up to 20 MB of runtime memory. It also show battery charge level. It's in the app store, has been spproved by Apple and ony costs $1. No hacks required and works with firmware versions 2.0 or later. Hoped this helps