Turn off Spotlight

Spotlight searches drives attached to Macs (OS 10.4 and above), indexing all the content it can find. This can be a nuisance for drives you attach temporarily to your computer, when you don't want the system to write to the drive. Here's one way to stop Spotlight, at least in OS 10.6, disabling indexing until you enable it with the second command. The problem is it only disables indexing drives currently attached:

sudo mdutil -a -i off

sudo mdutil -a -i on

I'm unsure whether leaving the -a option out turns indexing off for new drives, I guess something I could test.

sudo mdutil -i off