800Enabling root in OS X 10.7 (or 10.6)

sudo passwd root
After which you are prompted with a
Changing password for root.
New password:
Why the need for root? Surely, it’s a dangerous weapon and things can go awry easily, so only use it as a last resort. (I used it for hiding the couchdb account folder from the GUI.)

609Hide/Show Files in the Mac OSX GUI

Hiding files and folders from the Finder:
chflags hidden filename
And show them again:
chflags nohidden filename

139QC Show/Hide Private Patches

Run from Terminal: defaults write -g QCShowPrivatePatches 1 defaults write -g QCShowPrivatePatches 0