Ok, I've installed some Jailbreak-only software now. Well, a bit more that is..

Winterboard - a theme engine for the spring board. Not making extensive use of it yet and I haven't themed Springbord itself, but I'm using the hooks this provides for a few other things...

SBSettings - a quick pop-up to allow toggling various features/functions that would otherwise be buried in the settings app or in other apps. The default is to swipe on the top menu bar to pull this up. One of its other features is hiding applications, which I've already used to hide the Phone (can't use it with data-only), Messages (can't use it with data-only), Calculator, iPod, Clock, Notes and Stocks default apps. Along with hiding the Winterboard app icon since you can access its settings from the Settings app.

SBMatte theme icons - The only set of icons for SBSettingss that looked better than the originals - other themes are scary ugly. http://www.macthemes.net/forum/viewtopic.php?id=16793176

OpenSSH - nice being able to get to a command line remotely or use SFTP

iFIle - filesystem exploring right from the iPhone itself.

I want to install something to provide some status on the lock screen in addition to the time. There are a few things I'm looking at and will have to update once I've chosen. - LockInfo it is for now.