Reindex Spotlight
How do I reindex spotlight? And how often should I reindex it?
Mac OS X (10.6.7)
Launch the Spotlight Preference pane.
Drag the internal hard disk to the Privacy tab. (or any other disk that you want to re-index.
Quit.
Make a cup of tea or coffee! (i.e. wait a few seconds)
Relaunch.
Go to Privacy tab and remove the item you dragged there.
Spotlight will re-index (you'll see a pulsing dot in the middle of the magnifying glass).
I got this answer from somewhere else on this site. Credit due to the person who posted it.
There is a method using Terminal as well, if you prefer.