A while back, someone I've been unable to identify released this theme enabling the battery percentage in the iPhone status bar to appear in the Neutraface font. I've merely renamed the files to be compatible with Winterboard on iOS 5.
To install: extract the theme folder and upload to /private/var/stash/Themes.xxxxxx/, apply theme in Winterboard.
You may also copy the images in the file to the UIImages folder in the theme of your choice.
This package is not necessary for iOS 6. Battery percentage is font rendered in the new update.