Enabling 'root' is a way to access alot of extra power over the core system files, but it also gives the chance of royally screwing things up.
I found that a nifty little app, called
Cocktail which is at 2.0 (apparently a new interface though). I have 1.2 and it's a really nice tool. It has an empty trash function that can kill even the most stubborn of files.
Not to mention do all sorts of maintenance that is supposed to help streamline stuff or clear out old cache files from the system.
It's been a solid little tool for me.
I haven't looked at the new version (the posts at the site are not praising the new interface) but it's functionality is great. And you don't have to mess around in 'root'.
