My gripe:Why does Apple have to shove this tool down the user's throat by not making it, including that insipid menu, optional? Telling Spotlight to Ignore your hard drive won't delete existing indexes or databases. Telling Spotlight to ignore your hard drive wont turn off the now-useless menu.
Disclamer:
I really have no idea if this is the best or even a good way to do this. I want Spotlight gone. I only have Tiger to keep up to date, and I do not run out of date hardware or software.
So here's what I did...
[robg adds: Just a caution if you're going to try this -- I haven't tested it, and I have no idea what the implications may be on other programs that rely on Spotlight. Mail, for instance, uses Spotlight functionality for searching. I have no idea how this hack will affect Mail and the other Spotlight-enabled programs. Consider yourself warned...]
In the Terminal, do this:
$ sudo su
# chmod 0000 /Library/Spotlight
# chmod 0000 /System/Library/Spotlight
# chmod 0000 /System/Library/CoreServices/Search.bundle
# chmod 0000 /System/Library/PreferencePanes/Spotlight.prefPane
# chmod 0000 /System/Library/Services/Spotlight.service
# chmod 0000 /System/Library/Contextual Menu Items/SpotlightCM.plugin
# chmod 0000 /System/Library/StartupItems/Metadata
# chmod 0000 /usr/bin/mdimport
# chmod 0000 /usr/bin/mdcheckschema
# chmod 0000 /usr/bin/mdfind
# chmod 0000 /usr/bin/mdls
# chmod 0000 /usr/bin/mdutil
# chmod 0000 /usr/bin/md
After a reboot, open a new Terminal and do sudo su to make a root shell, then:
# rm -r /.Spotlight-V100
# rm -r /private/var/tmp/mds
# exit
Why use chmod? This hack can be reversed by repairing permissions.

