Your client work is caught up, your bug list is clear, and you have 8 free hours to throw at your application. Where do you put your time:

1. Cleaning up the UI
2. Shoring up the architecture
3. Updating your documentation
4. Usability testing
5. Something else?

All need attention, so what's the biggest bang for the buck...What takes precedence over all else? I've got to vote for UI, 'cause it is the application (though that's not the answer I'd have given a couple years ago).